I’m running v2.6.1 - Build: 20130506 on a site which I recently updated. After creating a new category and assigning that group to a channel, I attempted to edit entries with the new categories which I created. The above php error shows up on the entries for this particular channel. Researching the issue lead me to this bug fix. bug; however, checking the file identified as the source of the problem shows that system/expressionengine/fieldtypes/file/ft.file.php and the corresponding line is correct. Not sure how to proceed?