How to remove apps from nextcloud inside TrueNAS Scale

you are likely looking for occ

https://docs.nextcloud.com/server/latest/admin_manual/configuration_server/occ_command.html#maintenance-commands

you can remove an app with occ app:remove. with plain docker it’s like

docker exec --user www-data <nextcloud app container> php occ app:remove <app name>

or more specific in this case

docker exec --user www-data <nextcloud app container> php occ app:remove richdocumentscode

you are really wrong. we spend lot of time here to assist and understand the problem while silly admins are only looking for “quick fix”… from my feeling collabora-built-in aka richdocumentscode is freezing UI most often occurs on poorly administered devices where admins don’t know what they are doing and expect everything to work itself. but this integration is pretty complex - look at Nextcloud Collabora integration for details