Upgrader to Joomla 4 issue

While updating from J!3 --> J!4 I have seen a recurring issue. I keep PB, TC and MobileMenuPro installed during the upgrade and they don't cause an issue to the upgrade. However, there's a folder under plugins/pagbuilderck/contact which is causing the frontend to crash. Renaming the first to "contact1" or, for that matter, just deleting it fixes the issue. Not sure what it does on J!3 sites, but J!4 does not like it.

Hi
thank you for the info, I will try to fix it in the next install. This is an old plugin that is no more used since years, reason why it does not work on J4
CEd