When user deletes file that was attached on node, Filedepot reacts and throws PHP error message in Recent log entries:

Unknown column 'cckfd' in 'where clause' query: SELECT fid FROM filedepot_files WHERE cckfd=444 in /path/to/drupal/sites/all/modules/filedepot/filedepot.module on line 1175.

Looking at line 1175, it says:

$filedepot_fid = db_result(db_query("SELECT fid FROM {filedepot_files} WHERE cckfd=%d", $file->fid));

Then I did in MySQL
desc filedepot_files;
and get response:

+----------------------+---------------------+------+-----+---------+----------------+
| Field                | Type                | Null | Key | Default | Extra          |
+----------------------+---------------------+------+-----+---------+----------------+
| fid                  | mediumint(9)        | NO   | PRI | NULL    | auto_increment |
| cid                  | mediumint(9)        | NO   | MUL | 0       |                |
| fname                | varchar(255)        | NO   |     |         |                |
| title                | varchar(128)        | NO   |     |         |                |
| description          | longtext            | YES  |     | NULL    |                |
| version              | tinyint(3) unsigned | NO   |     | 1       |                |
| cckfid               | int(11)             | NO   |     | 0       |                |
| size                 | int(11)             | NO   |     | 0       |                |
| mimetype             | varchar(255)        | NO   |     |         |                |
| extension            | varchar(8)          | NO   |     |         |                |
| submitter            | mediumint(9)        | NO   |     | 0       |                |
| status               | tinyint(4)          | NO   |     | 0       |                |
| date                 | int(11)             | NO   |     | 0       |                |
| version_ctl          | tinyint(4)          | NO   |     | 0       |                |
| status_changedby_uid | mediumint(9)        | NO   |     | 0       |                |
+----------------------+---------------------+------+-----+---------+----------------+

Problem is that field is called CCKFID. In code, it is called cckfd instead cckfid.

How to fix:
- edit line 1175 in filedepot.module to look like:
$filedepot_fid = db_result(db_query("SELECT fid FROM {filedepot_files} WHERE cckfid=%d", $file->fid));