I am using Docker to set up Nextcloud and recently upgraded from Nextcloud 26 to Nextcloud 27 => 28 => 29. Collectives upgrade from 2.9.2 to 2.15.2. During the upgrade process, I did not encounter any errors, but I found that some users are unable to open certain files within Collectives. How can I resolve this issue? (Nextcloud has encryption enabled, using the Default encryption module.)
Can you elaborate as to what, specifically, happens? “unable to open” is kind of vague. 