Is the "deck" app gone for good?

I’m ever so very slowly making my way from version 20.0.0.7 up to the latest stable version, and seeing “Disabled incompatible app: deck” at least as of Nextcloud 23.

Is the Deck app actually dead or do I just need to do something to get it back?

Nah, it’s well alive. Should he updated to the latest version while upgrading your Nextcloud instance. Of course make a backup before performing the upgrade.

Check out the compatible versions here: https://apps.nextcloud.com/apps/deck

Thanks. It does seem to be working fine. Not sure why it was giving me errors while I upgraded but I guess that’s what I get for getting five major releases behind.