Project Saving Crash

Hi,

I am having problems saving a particular project. All was working fine a couple of days ago, but when I try to save a particular project, Cubase 11 hangs and then crashes. It also creates a new 01.cpr file, which cannot be opened. I get the error message. '… was create with Cubase 1.x. This program cannot load it.

Can anyone advise?

Thanks!

Attatched crash report
Cubase 11_2020-11-21-133433_Harrys-MacBook-Pro.crash (468 KB)