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
We have resolved the issue with the J! updater and this will be fixed in the next release.
Another problem with ajaxified lists and calculation positions is that the buttons (ex. delete, update record) near the elements labels (headers) are missing.
See the image:
View attachment 12108