I recently upgraded to 2.9.14 from 2.9 in the hopes that this would fix the visual editor button, and subsequently no users were able to download files from categories restricted to their user level. I tried cursively reapplying permissions in the categories settings but this did not work. Specifically, the attached files were not even shown in posts for these users.
I have been forced to revert to an earlier version to restore this core functionality. The problem occurs due to the "Multiple roles file permissions" feature introduced in 2.9.1 Specifically, the codes does not seem to act appropriately when upgrading from earlier systems, and sets the restricted user level of a file to match that of the category rather than set it to that level, and anything higher. For users with hundreds of files managed by your plug-in, this is a major impediment to upgrading.