No booting. 10.15 beta 1
As I wrote earlier, the problem is not in beta 1. This happened after cleaning and removing TeamViwer through the program Cleanmymac X. In safe mode, the same error.
I have encountered something similar using CleanMyMac X for removing something (I don't remember what though). My Mac booted ok though, but I had to reinstall the software that Cleanmymac had removed to make the problem go away.
Strange that this still happens during a safe mode restart??!!
From a Google search it looks like there may be a bundle that hasn't been deleted and is trying to activate software that has been deleted. If you can't boot in safe mode you may have to boot in recovery mode then use Terminal to search for, and remove, the bundle at:
If that doesn't exist, then the problem could be that something during startup is trying to reference that non-existent bundle. That might be trickier to determine and might need help from TeamViewer Support.
At this point Alexander, I think I would boot from a clone (hopefully you made one before trying the beta) and just reformat the drive and reinstall from scratch Catalina beta 1.
Sorry, I appreciate that English might not be easy for you, but that screenshot doesn’t give me any more information about what you found. (Looks like you found the bundle elsewhere & copied it onto an installer USB and you were trying to then copy it into the boot volume?)
Also, I’m still confused about the version of macOS. The subject title indicates “10.15 beta 1” but you later say that’s not the problem. 10.15 pretty certainly has a different security framework so if you *are* using that version of macOS the problem may be something completely new.