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.
When did you commit this? If it was last week, then the problem has not been resolved. If you committed after my last post 2 days ago, then I will update and check.
The problem was the highlight in IE9 of ALL the content.
Paul