Can no longer save settings in theme panel

Since updating Newsmag I can no longer save settings within the Newsmag Theme Panel. All I get is the squares spinning, but no confirmation that the settings have been saved.

Hi

Try to deactivate all plugins except Visual Composer, clear all caches and test again. Also check the browser console for any errors while you’re saving the settings. Usually there should appear a 403 or 404 error. If this happens contact your server administrator and explain the situation, as it’s requested many times during the a save the file it’s treated as threat so it’s banned. You can report false positives to your server administrator to remove it from the banned list.

Thanks!