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
http://fabrikar.com/forums/index.php?wiki/joomla-user-form-plugin/Note if you want to update the Joomla user associated with the form's record when you edit the form's data you must supply a field (type field or dbjoin) in the "User ID field"
Site needs addionally htaccess password.
You have set element access form(add) to registered.
So a new user (which doesn't exist at this moment and is not logged) in doesn't have access to this element, so the userid can't be written.
I can't get in to look because of the htaccess. Either set that password to the same as the admin one we use, or disable it, until we're done with this issue.
I can't replicate the problem here, the userid gets set OK in my juser tests, so it has to be something with your setup, so I need to log in.
-- hugh
I'm trying to submit the form to test it, but the "Major" dropdown has a validation on it and no options.
-- hugh
return JFactory::getUser()->guest;
$myUser = JFactory::getUser();
return $myUser->guest || $myUser->get('id') == $formModel->formData['yourtable___userid_raw'];