Updated and wont connect to Printer

What is the problem?
When I update to latest version I cant connect to my printer, it just keeps telling me that no baudrates left.

What did you already try to solve it?

I tried all I could find about it on the net and this board, but nothing worked, the only way I can get it to work again is to install version Octoprint 1.3.8 and Octopi 0.15.1.

But as soon as I update to the latest version it will not connect to the printer.

Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, octoprint.log, serial.log or output on terminal tab, ...)

Prusa Mk3 MMU2 Octoprint/Octopi versions as above. and I am using TheZeroBeast Firmware ver 2.1.8 RC2 B#: 304**