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
Please see our announcement here.
$rowid = $formModel->formData['rowid'];
if (!empty($rowid)) {
$myId = sprintf('%04f', $rowid);
$myDb = JFactory::GetDbo();
$myQuery = $myDb->getQuery(true);
$myQuery->update('yourtable')-.>set('yourid = ' . $db->quote($myId))->where('id = ' . $myDb->quote($rowid));
$myDb->setQuery($myQuery);
$myDb->execute();
}