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 are still working on the Joomla update.
Yes! That's it exactly Thank you.You mean indicating that the user has really changed something, not only opened the form?
Ah ok -- now we know.
I guess that could mean, a warning appears as soon as a user interacts with the form. IMO, the simplest solution should be some custom Javascript that, if the user clicks anywhere within the <form> tag, displays a div containing the warning, e.g. in a fixed position in one of the corners of the viewport.
"Custom" indicating that Fabrik does not have this on board out of the box, obviously. So, it'd need to be added by you, e.g. by following the link here above.