diff --git a/src/obidms.c b/src/obidms.c
index a0c1d9f..ed42f82 100644
--- a/src/obidms.c
+++ b/src/obidms.c
@@ -17,6 +17,7 @@
 #include "obidebug.h"
 #include "obidmscolumn.h"
 
+
 #define DEBUG_LEVEL 0
 
 
@@ -65,6 +66,7 @@ static char *build_directory_name(const char *dms_name)
 	if (asprintf(&directory_name, "%s.obidms", dms_name) < 0)
 	{
 		obi_set_errno(OBIDMS_MEMORY_ERROR);
+		obidebug(1, "\nProblem building an OBIDMS directory name");
 		return NULL;
 	}
 
@@ -72,6 +74,7 @@ static char *build_directory_name(const char *dms_name)
 	if (strlen(directory_name) >= OBIDMS_MAX_NAME)
 	{
 		obi_set_errno(OBIDMS_LONG_NAME_ERROR);
+		obidebug(1, "\nProblem building an OBIDMS directory name");
 		free(directory_name);
 		return NULL;
 	}
@@ -124,7 +127,7 @@ OBIDMS_p obi_create_dms(const char* dms_name)
 			obi_set_errno(OBIDMS_EXIST_ERROR);
 		else
 			obi_set_errno(OBIDMS_UNKNOWN_ERROR);
-
+		obidebug(1, "\nProblem creating an OBIDMS directory");
 		free(directory_name);
 		return NULL;
 	}
@@ -152,7 +155,6 @@ OBIDMS_p obi_open_dms(const char* dms_name)
 	directory = opendir(directory_name);
 	if (directory == NULL)
 	{
-		obidebug(1, "Can't open DMS");
 		switch (errno)
 		{
 			case ENOENT:
@@ -170,6 +172,7 @@ OBIDMS_p obi_open_dms(const char* dms_name)
 			default:
 				obi_set_errno(OBIDMS_UNKNOWN_ERROR);
 		}
+		obidebug(1, "\nCan't open OBIDMS directory");
 		free(directory_name);
 		return NULL;
 	}
@@ -179,6 +182,7 @@ OBIDMS_p obi_open_dms(const char* dms_name)
 	if (dms == NULL)
 	{
 		obi_set_errno(OBIDMS_MEMORY_ERROR);
+		obidebug(1, "\nError allocating the memory for the OBIDMS structure");
 		free(directory_name);
 		return NULL;
 	}
@@ -207,6 +211,7 @@ OBIDMS_p obi_dms(const char* dms_name)
 			return obi_open_dms(dms_name);
 	};
 
+	obidebug(1, "\nError checking if an OBIDMS directory exists");
 	return NULL;
 }
 
@@ -223,6 +228,11 @@ int obi_list_columns(OBIDMS_p dms)
   d = dms->directory;
 
   dir = readdir(d);
+  if (dir == NULL)
+  {
+	  obidebug(1, "\nError reading in the OBIDMS directory");
+	  return -1;
+  }
 
   fprintf(stderr, "Column name\tData type\tLatest version");
 
@@ -250,7 +260,7 @@ int obi_list_columns(OBIDMS_p dms)
 
   rewinddir(d);
 
-  return(0);
+  return 0;
 }
 
 
@@ -261,6 +271,7 @@ int obi_close_dms(OBIDMS_p dms)
 		if (closedir(dms->directory) < 0)
 		{
 			obi_set_errno(OBIDMS_MEMORY_ERROR);
+			obidebug(1, "\nError closing an OBIDSM directory");
 			free(dms);
 			return -1;
 		}
diff --git a/src/obidmscolumn.c b/src/obidmscolumn.c
index 648a937..f4f4511 100644
--- a/src/obidmscolumn.c
+++ b/src/obidmscolumn.c
@@ -152,7 +152,7 @@ static char *build_column_file_name(const char *column_name, obiversion_t versio
 	if (asprintf(&filename,"%s@%d.odc", column_name, version_number) < 0)
 	{
 		obi_set_errno(OBICOL_MEMORY_ERROR);
-		obidebug(1, "\nasprintf() function failed");
+		obidebug(1, "\nError building a column file name");
 		return NULL;
 	}
 
@@ -168,6 +168,7 @@ static char *build_version_file_name(const char *column_name)
 	if (asprintf(&filename,"%s.odv", column_name) < 0)
 	{
 		obi_set_errno(OBICOL_MEMORY_ERROR);
+		obidebug(1, "\nError building a version file name");
 		return NULL;
 	}
 
@@ -204,6 +205,7 @@ static obiversion_t obi_get_new_version_number(OBIDMS_column_directory_p column_
 	if (column_dir_file_descriptor < 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError getting the file descriptor for a column file directory");
 		free(version_file_name);
 		return -1;
 	}
@@ -212,7 +214,6 @@ static obiversion_t obi_get_new_version_number(OBIDMS_column_directory_p column_
 	version_file_descriptor = openat(column_dir_file_descriptor, version_file_name, O_RDWR);
 	if (version_file_descriptor < 0)
 	{
-		free(version_file_name);
 		if (errno == ENOENT)
 			return create_version_file(column_directory);
 		else
@@ -220,14 +221,16 @@ static obiversion_t obi_get_new_version_number(OBIDMS_column_directory_p column_
 			obi_set_errno(OBICOL_UNKNOWN_ERROR);
 			return -1;
 		}
+		obidebug(1, "\nError opening a version file");
+		free(version_file_name);
 	}
 
 	// Test if the version file size is ok
 	if (lseek(version_file_descriptor, 0, SEEK_END) < loc_size)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError testing if a version file size is ok");
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		free(version_file_name);
 		return -1;
 	}
@@ -236,8 +239,8 @@ static obiversion_t obi_get_new_version_number(OBIDMS_column_directory_p column_
 	if (lseek(version_file_descriptor, 0, SEEK_SET) != 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError preparing a version file for locking");
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		free(version_file_name);
 		return -1;
 	}
@@ -246,8 +249,8 @@ static obiversion_t obi_get_new_version_number(OBIDMS_column_directory_p column_
 	if (lockf(version_file_descriptor, lock_mode, loc_size) < 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError locking a version file");
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		free(version_file_name);
 		return -1;
 	}
@@ -256,8 +259,8 @@ static obiversion_t obi_get_new_version_number(OBIDMS_column_directory_p column_
     if (read(version_file_descriptor, &little_endian, sizeof(bool)) < sizeof(bool))
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError reading the endianness of a version file");
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		free(version_file_name);
 		return -1;
 	}
@@ -266,8 +269,8 @@ static obiversion_t obi_get_new_version_number(OBIDMS_column_directory_p column_
     if (little_endian != obi_is_little_endian())
 	{
 		obi_set_errno(OBICOL_BAD_ENDIAN_ERROR);
+		obidebug(1, "\nEndianness of a version file is incorrect");
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		free(version_file_name);
 		return -1;
 	}
@@ -276,8 +279,8 @@ static obiversion_t obi_get_new_version_number(OBIDMS_column_directory_p column_
     if (read(version_file_descriptor, &new_version_number, sizeof(obiversion_t)) < sizeof(obiversion_t))
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError reading a version file");
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		free(version_file_name);
 		return -1;
 	}
@@ -288,8 +291,8 @@ static obiversion_t obi_get_new_version_number(OBIDMS_column_directory_p column_
 	if (lseek(version_file_descriptor, sizeof(bool), SEEK_SET) != sizeof(bool))
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError writing a new version number in a version file");
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		free(version_file_name);
 		return -1;
 	}
@@ -297,8 +300,8 @@ static obiversion_t obi_get_new_version_number(OBIDMS_column_directory_p column_
 	if (write(version_file_descriptor, &new_version_number, sizeof(obiversion_t)) < sizeof(obiversion_t))
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError writing a new version number in a version file");
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		free(version_file_name);
 		return -1;
 	}
@@ -307,8 +310,8 @@ static obiversion_t obi_get_new_version_number(OBIDMS_column_directory_p column_
 	if (lseek(version_file_descriptor, 0, SEEK_SET) != 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError preparing the unlocking of a version file");
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		free(version_file_name);
 		return -1;
 	}
@@ -317,8 +320,8 @@ static obiversion_t obi_get_new_version_number(OBIDMS_column_directory_p column_
 	if (lockf(version_file_descriptor, F_ULOCK, loc_size) < 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError unlocking a version file");
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		free(version_file_name);
 		return -1;
 	}
@@ -351,6 +354,7 @@ static int create_version_file(OBIDMS_column_directory_p column_directory)
 	if (column_dir_file_descriptor < 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError getting the file descriptor for a column directory");
 		free(version_file_name);
 		return -1;
 	}
@@ -360,8 +364,8 @@ static int create_version_file(OBIDMS_column_directory_p column_directory)
 	if (version_file_descriptor < 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError opening a version file");
 		free(version_file_name);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -369,9 +373,9 @@ static int create_version_file(OBIDMS_column_directory_p column_directory)
 	if (lockf(version_file_descriptor, F_LOCK, loc_size) < 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError locking a version file");
 		free(version_file_name);
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -379,9 +383,9 @@ static int create_version_file(OBIDMS_column_directory_p column_directory)
 	if (ftruncate(version_file_descriptor, loc_size) < 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError truncating a version file");
 		free(version_file_name);
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -389,9 +393,9 @@ static int create_version_file(OBIDMS_column_directory_p column_directory)
 	if (lseek(version_file_descriptor, 0, SEEK_SET) != 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError changing offset of a version file");
 		free(version_file_name);
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -401,9 +405,9 @@ static int create_version_file(OBIDMS_column_directory_p column_directory)
 	if (write(version_file_descriptor, &little_endian, sizeof(bool)) < sizeof(bool))
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError writing endianness of a version file");
 		free(version_file_name);
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -411,9 +415,9 @@ static int create_version_file(OBIDMS_column_directory_p column_directory)
 	if (write(version_file_descriptor, &version_number, sizeof(obiversion_t)) < sizeof(obiversion_t))
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError writing version number in a version file");
 		free(version_file_name);
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -421,9 +425,9 @@ static int create_version_file(OBIDMS_column_directory_p column_directory)
 	if (lseek(version_file_descriptor, 0, SEEK_SET) != 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError preparing a version file for unlocking");
 		free(version_file_name);
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -431,9 +435,9 @@ static int create_version_file(OBIDMS_column_directory_p column_directory)
 	if (lockf(version_file_descriptor, F_ULOCK, loc_size) < 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError unlocking a version file");
 		free(version_file_name);
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -448,7 +452,10 @@ int obi_column_set_elements_names(OBIDMS_column_p column, const char* elements_n
 {
 	(column->header)->elements_names = malloc(strlen(elements_names)*sizeof(char) + 1);
 	if ((column->header)->elements_names == NULL)
+	{
+		obidebug(1, "\nError allocating the memory for elements names in an OBIDMS column");
 		return -1;
+	}
 	strcpy((column->header)->elements_names, elements_names);
 	return 0;
 }
@@ -481,6 +488,7 @@ obiversion_t obi_get_latest_version_number(OBIDMS_column_directory_p column_dire
 	if (column_dir_file_descriptor < 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError getting the file descriptor for a column directory");
 		free(version_file_name);
 		return -1;
 	}
@@ -490,8 +498,8 @@ obiversion_t obi_get_latest_version_number(OBIDMS_column_directory_p column_dire
 	if (version_file_descriptor < 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError opening a version file");
 		free(version_file_name);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -499,9 +507,9 @@ obiversion_t obi_get_latest_version_number(OBIDMS_column_directory_p column_dire
 	if (lseek(version_file_descriptor, 0, SEEK_END) < loc_size)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError testing if a version file size is ok");
 		free(version_file_name);
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -509,9 +517,9 @@ obiversion_t obi_get_latest_version_number(OBIDMS_column_directory_p column_dire
 	if (lseek(version_file_descriptor, 0, SEEK_SET) != 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError setting the offset of a version file to 0");
 		free(version_file_name);
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -519,9 +527,9 @@ obiversion_t obi_get_latest_version_number(OBIDMS_column_directory_p column_dire
     if (read(version_file_descriptor, &little_endian, sizeof(bool)) < sizeof(bool))
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError reading the endianness of a version file");
 		free(version_file_name);
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -529,9 +537,9 @@ obiversion_t obi_get_latest_version_number(OBIDMS_column_directory_p column_dire
     if (little_endian != obi_is_little_endian())
 	{
 		obi_set_errno(OBICOL_BAD_ENDIAN_ERROR);
+		obidebug(1, "\nEndianness of a version file is incorrect");
 		free(version_file_name);
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -539,9 +547,9 @@ obiversion_t obi_get_latest_version_number(OBIDMS_column_directory_p column_dire
     if (read(version_file_descriptor, &latest_version_number, sizeof(obiversion_t)) < sizeof(obiversion_t))
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError reading the latest version number in a version file");
 		free(version_file_name);
 		close(version_file_descriptor);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -561,7 +569,7 @@ obiversion_t obi_column_get_latest_version_from_name(OBIDMS_p dms, const char* c
 	column_directory = obi_open_column_directory(dms, column_name);
 	if (column_directory == NULL)
 	{
-		obidebug(1, "\nProblem opening column directory");
+		obidebug(1, "\nProblem opening a column directory structure");
 		return -1;
 	}
 
@@ -569,8 +577,7 @@ obiversion_t obi_column_get_latest_version_from_name(OBIDMS_p dms, const char* c
 	latest_version = obi_get_latest_version_number(column_directory);
 	if (latest_version < 0)
 	{
-		obidebug(1, "\nProblem getting the latest version number");
-		obi_close_column_directory(column_directory);
+		obidebug(1, "\nProblem getting the latest version number in a column directory");
 		return -1;
 	}
 
@@ -604,19 +611,23 @@ OBIDMS_column_p obi_create_column(OBIDMS_p dms,
 
 	new_column = NULL;
 
-	// TODO check that informations are not NULL/invalid
+	// TODO check that informations are not NULL/invalid?
 
 	// Get the column directory structure associated to the column
 	column_directory = obi_column_directory(dms, column_name);
 	if (column_directory == NULL)
+	{
+		obi_set_errno(OBICOLDIR_UNKNOWN_ERROR);
+		obidebug(1, "\nError opening a column directory structure");
 		return NULL;
+	}
 
 	// Get the file descriptor associated to the column directory
 	column_dir_file_descriptor = dirfd(column_directory->directory);
 	if (column_dir_file_descriptor < 0)
 	{
 		obi_set_errno(OBICOLDIR_UNKNOWN_ERROR);
-		obi_close_column_directory(column_directory);
+		obidebug(1, "\nError getting the file descriptor for a column directory");
 		return NULL;
 	}
 
@@ -629,8 +640,6 @@ OBIDMS_column_p obi_create_column(OBIDMS_p dms,
 	version_number = obi_get_new_version_number(column_directory, true);
 	if (version_number < 0)
 	{
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
 		return NULL;
 	}
 
@@ -638,8 +647,6 @@ OBIDMS_column_p obi_create_column(OBIDMS_p dms,
 	column_file_name = build_column_file_name(column_name, version_number);
 	if (column_file_name == NULL)
 	{
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
 		return NULL;
 	}
 
@@ -648,8 +655,6 @@ OBIDMS_column_p obi_create_column(OBIDMS_p dms,
 	if (column_file_descriptor < 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
 		free(column_file_name);
 		return NULL;
 	}
@@ -658,8 +663,7 @@ OBIDMS_column_p obi_create_column(OBIDMS_p dms,
 	if (ftruncate(column_file_descriptor, file_size) < 0)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
+		obidebug(1, "\nError truncating a column file to the right size");
 		close(column_file_descriptor);
 		free(column_file_name);
 		return NULL;
@@ -670,8 +674,7 @@ OBIDMS_column_p obi_create_column(OBIDMS_p dms,
 	if (new_column == NULL)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
+		obidebug(1, "\nError allocating the memory for the column structure");
 		close(column_file_descriptor);
 		free(column_file_name);
 		return NULL;
@@ -691,8 +694,7 @@ OBIDMS_column_p obi_create_column(OBIDMS_p dms,
 	if (new_column->header == MAP_FAILED)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
+		obidebug(1, "\nError mmapping the header of a column");
 		close(column_file_descriptor);
 		free(column_file_name);
 		free(new_column);
@@ -709,10 +711,9 @@ OBIDMS_column_p obi_create_column(OBIDMS_p dms,
 
 	if (new_column->data == MAP_FAILED)
 	{
-		munmap(new_column->header, header_size);
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
+		obidebug(1, "\nError mmapping the data of a column");
+		munmap(new_column->header, header_size);
 		close(column_file_descriptor);
 		free(column_file_name);
 		free(new_column);
@@ -759,7 +760,7 @@ OBIDMS_column_p obi_open_column(OBIDMS_p dms, const char* column_name, obiversio
 	column_directory = obi_open_column_directory(dms, column_name);
 	if (column_directory == NULL)
 	{
-		obidebug(1, "\nProblem opening column directory");
+		obidebug(1, "\nError opening a column directory structure");
 		return NULL;
 	}
 
@@ -767,9 +768,8 @@ OBIDMS_column_p obi_open_column(OBIDMS_p dms, const char* column_name, obiversio
 	column_dir_file_descriptor = dirfd(column_directory->directory);
 	if (column_dir_file_descriptor < 0)
 	{
-		obidebug(1, "\nProblem opening column directory");
 		obi_set_errno(OBICOLDIR_UNKNOWN_ERROR);
-		obi_close_column_directory(column_directory);
+		obidebug(1, "\nError getting the file descriptor for a column directory");
 		return NULL;
 	}
 
@@ -782,9 +782,7 @@ OBIDMS_column_p obi_open_column(OBIDMS_p dms, const char* column_name, obiversio
 		version_number = obi_get_latest_version_number(column_directory);
 		if (version_number < 0)
 		{
-			obidebug(1, "\nProblem getting the latest version number");
-			obi_close_column_directory(column_directory);
-			close(column_dir_file_descriptor);
+			obidebug(1, "\nError getting the latest version number in a column directory");
 			return NULL;
 		}
 	}
@@ -793,9 +791,6 @@ OBIDMS_column_p obi_open_column(OBIDMS_p dms, const char* column_name, obiversio
 	column_file_name = build_column_file_name(column_name, version_number);
 	if (column_file_name == NULL)
 	{
-		obidebug(1, "Problem building column file name");
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
 		return NULL;
 	}
 
@@ -803,10 +798,8 @@ OBIDMS_column_p obi_open_column(OBIDMS_p dms, const char* column_name, obiversio
 	column_file_descriptor = openat(column_dir_file_descriptor, column_file_name, O_RDONLY);
 	if (column_file_descriptor < 0)
 	{
-		obidebug(1, "\nCan't open column file");
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
+		obidebug(1, "\nError opening column file");
 		free(column_file_name);
 		return NULL;
 	}
@@ -816,8 +809,7 @@ OBIDMS_column_p obi_open_column(OBIDMS_p dms, const char* column_name, obiversio
 	if (column == NULL)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
+		obidebug(1, "\nError allocating the memory for a column structure");
 		close(column_file_descriptor);
 		free(column_file_name);
 		return NULL;
@@ -837,8 +829,7 @@ OBIDMS_column_p obi_open_column(OBIDMS_p dms, const char* column_name, obiversio
 	if (column->header == MAP_FAILED)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
+		obidebug(1, "\nError mmapping the header of a column");
 		close(column_file_descriptor);
 		free(column_file_name);
 		free(column);
@@ -860,10 +851,9 @@ OBIDMS_column_p obi_open_column(OBIDMS_p dms, const char* column_name, obiversio
 
 	if (column->data == MAP_FAILED)
 	{
-		munmap(column->header, header_size);
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
+		obidebug(1, "\nError mmapping the data of a column");
+		munmap(column->header, header_size);
 		close(column_file_descriptor);
 		free(column_file_name);
 		free(column);
@@ -881,7 +871,7 @@ OBIDMS_column_p obi_open_column(OBIDMS_p dms, const char* column_name, obiversio
 
 int obi_close_column(OBIDMS_column_p column)
 {
-	//munmap?
+	//munmap? TODO
 	free(column);
 	return 0;
 }
@@ -920,7 +910,7 @@ OBIType_t obi_column_get_data_type_from_name(OBIDMS_p dms, const char* column_na
 	column_directory = obi_open_column_directory(dms, column_name);
 	if (column_directory == NULL)
 	{
-		obidebug(1, "\nProblem opening column directory");
+		obidebug(1, "\nError opening a column directory structure");
 		return -1;
 	}
 
@@ -928,8 +918,8 @@ OBIType_t obi_column_get_data_type_from_name(OBIDMS_p dms, const char* column_na
 	column_dir_file_descriptor = dirfd(column_directory->directory);
 	if (column_dir_file_descriptor < 0)
 	{
-		obidebug(1, "\nProblem opening column directory");
 		obi_set_errno(OBICOLDIR_UNKNOWN_ERROR);
+		obidebug(1, "\nError getting the file descriptor of a column directory");
 		obi_close_column_directory(column_directory);
 		return -1;
 	}
@@ -941,9 +931,7 @@ OBIType_t obi_column_get_data_type_from_name(OBIDMS_p dms, const char* column_na
 	version_number = obi_get_latest_version_number(column_directory);
 	if (version_number < 0)
 	{
-		obidebug(1, "\nProblem getting the latest version number");
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
+		obidebug(1, "\nError getting the latest version number in a column directory");
 		return -1;
 	}
 
@@ -951,9 +939,6 @@ OBIType_t obi_column_get_data_type_from_name(OBIDMS_p dms, const char* column_na
 	column_file_name = build_column_file_name(column_name, version_number);
 	if (column_file_name == NULL)
 	{
-		obidebug(1, "Problem building column file name");
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
 		return -1;
 	}
 
@@ -961,10 +946,8 @@ OBIType_t obi_column_get_data_type_from_name(OBIDMS_p dms, const char* column_na
 	column_file_descriptor = openat(column_dir_file_descriptor, column_file_name, O_RDONLY);
 	if (column_file_descriptor < 0)
 	{
-		obidebug(1, "\nCan't open column file");
+		obidebug(1, "\nError opening a column file");
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
 		free(column_file_name);
 		return -1;
 	}
@@ -981,11 +964,9 @@ OBIType_t obi_column_get_data_type_from_name(OBIDMS_p dms, const char* column_na
 	if (header == MAP_FAILED)
 	{
 		obi_set_errno(OBICOL_UNKNOWN_ERROR);
-		obi_close_column_directory(column_directory);
-		close(column_dir_file_descriptor);
+		obidebug(1, "\nError mmapping the header of a column");
 		close(column_file_descriptor);
 		free(column_file_name);
-		free(header);
 		return -1;
 	}
 
@@ -1041,7 +1022,7 @@ size_t obi_column_get_element_index_from_name(OBIDMS_column_p column, const char
 		element_index++;
 	}
 
-	obidebug(1, "\nCan't find element name");
+	obidebug(1, "\nCan't find an element name");
 	free(elements_names);
 	return -1;
 }
diff --git a/src/obidmscolumndir.c b/src/obidmscolumndir.c
index d292cc7..6f7dcd0 100644
--- a/src/obidmscolumndir.c
+++ b/src/obidmscolumndir.c
@@ -22,6 +22,10 @@
 #include "obidms.h"
 #include "private_at_functions.h"
 #include "obierrno.h"
+#include "obidebug.h"
+
+
+#define DEBUG_LEVEL 0
 
 
 /**************************************************************************
@@ -69,6 +73,7 @@ static char* build_column_directory_name(const char* column_name)
 	if (asprintf(&column_directory_name, "%s.obicol", column_name) < 0)
 	{
 		obi_set_errno(OBICOLDIR_MEMORY_ERROR);
+		obidebug(1, "\nError building a column directory name");
 		return NULL;
 	}
 
@@ -76,6 +81,7 @@ static char* build_column_directory_name(const char* column_name)
 	if (strlen(column_directory_name) >= OBIDMS_COLUMN_DIR_MAX_NAME)
 	{
 		obi_set_errno(OBICOLDIR_LONG_NAME_ERROR);
+		obidebug(1, "\nError building a column directory name");
 		free(column_directory_name);
 		return NULL;
 	}
@@ -101,16 +107,14 @@ int obi_column_directory_exists(OBIDMS_p dms, const char* column_name)
 	// Build and check the directory name
     column_directory_name = build_column_directory_name(column_name);
 	if (column_directory_name == NULL)
-	{
-		obi_set_errno(OBICOLDIR_UNKNOWN_ERROR);
 		return -1;
-	}
 
 	// Get the file descriptor for the dms
 	dms_file_descriptor = dirfd(dms->directory);
 	if (dms_file_descriptor < 0)
 	{
 		obi_set_errno(OBIDMS_UNKNOWN_ERROR);
+		obidebug(1, "\nError getting a file descriptor for an OBIDMS directory");
 		free(column_directory_name);
 		return -1;
 	}
@@ -120,6 +124,7 @@ int obi_column_directory_exists(OBIDMS_p dms, const char* column_name)
 	if (full_path == NULL)
 	{
 		obi_set_errno(OBICOLDIR_UNKNOWN_ERROR);
+		obidebug(1, "\nError getting path for an OBIDMS directory");
 		free(column_directory_name);
 		return -1;
 	}
@@ -154,6 +159,7 @@ OBIDMS_column_directory_p obi_create_column_directory(OBIDMS_p dms, const char*
 	if (dms_file_descriptor < 0)
 	{
 		obi_set_errno(OBIDMS_UNKNOWN_ERROR);
+		obidebug(1, "\nError getting a file descriptor for an OBIDMS directory");
 		free(column_directory_name);
 		return NULL;
 	}
@@ -165,8 +171,8 @@ OBIDMS_column_directory_p obi_create_column_directory(OBIDMS_p dms, const char*
 			obi_set_errno(OBICOLDIR_EXIST_ERROR);
 		else
 			obi_set_errno(OBICOLDIR_UNKNOWN_ERROR);
+		obidebug(1, "\nError creating a column directory");
 		free(column_directory_name);
-		close(dms_file_descriptor);
 		return NULL;
 	}
 
@@ -179,9 +185,9 @@ OBIDMS_column_directory_p obi_create_column_directory(OBIDMS_p dms, const char*
 OBIDMS_column_directory_p obi_open_column_directory(OBIDMS_p dms, const char* column_name)
 {
 	OBIDMS_column_directory_p	column_directory;
-	char*	 				column_directory_name;
-	DIR*					directory;
-	int 					dms_file_descriptor;
+	char*	 					column_directory_name;
+	DIR*						directory;
+	int 						dms_file_descriptor;
 
 	column_directory = NULL;
 
@@ -195,6 +201,7 @@ OBIDMS_column_directory_p obi_open_column_directory(OBIDMS_p dms, const char* co
 	if (dms_file_descriptor < 0)
 	{
 		obi_set_errno(OBIDMS_UNKNOWN_ERROR);
+		obidebug(1, "\nError getting a file descriptor for an OBIDMS directory");
 		free(column_directory_name);
 		return NULL;
 	}
@@ -219,8 +226,8 @@ OBIDMS_column_directory_p obi_open_column_directory(OBIDMS_p dms, const char* co
 			default:
 				obi_set_errno(OBICOLDIR_UNKNOWN_ERROR);
 		}
+		obidebug(1, "\nError opening a column directory");
 		free(column_directory_name);
-		close(dms_file_descriptor);
 		return NULL;
 	}
 
@@ -229,8 +236,8 @@ OBIDMS_column_directory_p obi_open_column_directory(OBIDMS_p dms, const char* co
 	if (column_directory == NULL)
 	{
 		obi_set_errno(OBICOLDIR_MEMORY_ERROR);
+		obidebug(1, "\nError allocating the memory for an OBIDMS column directory structure");
 		free(column_directory_name);
-		close(dms_file_descriptor);
 		return NULL;
 	}
 
@@ -258,6 +265,7 @@ OBIDMS_column_directory_p obi_column_directory(OBIDMS_p dms, const char* column_
 			return obi_open_column_directory(dms, column_name);
 	};
 
+	obidebug(1, "\nError checking if a column directory exists");
 	return NULL;
 }
 
@@ -270,6 +278,7 @@ int obi_close_column_directory(OBIDMS_column_directory_p column_directory)
 		if (closedir(column_directory->directory) < 0)
 		{
 			obi_set_errno(OBICOLDIR_MEMORY_ERROR);
+			obidebug(1, "\nError closing a column directory");
 			free(column_directory);
 			return -1;
 		}
diff --git a/src/private_at_functions.c b/src/private_at_functions.c
index ebb9fb7..3383a5f 100644
--- a/src/private_at_functions.c
+++ b/src/private_at_functions.c
@@ -19,6 +19,11 @@
 #include <dirent.h>
 
 #include "private_at_functions.h"
+#include "obidebug.h"
+#include "obierrno.h"
+
+
+#define DEBUG_LEVEL 0
 
 
 /**********************************************************************
@@ -34,12 +39,18 @@ char* get_full_path(int directory_file_descriptor, const char* path_name)
 
 	full_path = (char*) malloc((MAX_PATH_LEN)*sizeof(char));
 	if (full_path == NULL)
+	{
+		obidebug(1, "\nError allocating memory for the char* path to a file or directory");
 		return NULL;
+	}
 
 	if (fcntl(directory_file_descriptor, F_GETPATH, full_path) < 0)
+	{
+		obidebug(1, "\nError getting the path to a file or directory");
 		return NULL;
+	}
 
-	// check errors  TODO
+	// TODO check errors
 	strlcat(full_path, "/", MAX_PATH_LEN);
 	strlcat(full_path, path_name, MAX_PATH_LEN);
 
@@ -57,6 +68,8 @@ DIR* private_opendirat(int directory_file_descriptor, const char* path_name)
 		return NULL;
 
 	directory = opendir(full_path);
+	if (directory == NULL)
+		obidebug(1, "\nError opening a directory");
 
 	free(full_path);