For running J!5.1 you must https://fabrikar.com/forums/index.php?wiki/update-from-github/ or include the new file manually https://fabrikar.com/forums/index.php?threads/joomla-5-1-and-fabrik-cannot-find-files-error.54473/post-285151 See also Announcements
See Announcement
Please post subscription issues here
We have resolved the issue with the J! updater and this will be fixed in the next release.
As often as you need a bugfix or a new features provided in GitHubUpdate from GitHub
Only if you want to install a new plugin.Go to Extensions > Extension Manager > Discover
Click 'Purge Cache' and then 'Discover'
Select your plugins and click 'Install'
Go to Extensions > Plug-in Manager
Enable your plugins
And whenever something isn't working correctly on your site, I've learned to NEVER post on the forum until you update from github first. It's fixed 50% of my issues. Hahaha.
PS - You post A LOT. Holy CRAP!!!!! (And I'm saying that in a nice calm voice, but rolling my eyes slightly).