Yep, I'm in, thanks.

I am also having the same issue, thank you. Have already deleted everything (FAF and supcom) and reinstalled.

The same error:
Client Version: 2023.11.1
java.lang.NullPointerException: Cannot invoke "java.lang.Process.onExit()" because "process" is null

I think maybe the 2023.11 update initially failed in an odd and unrecoverable way, which seems like the root cause. I could not launch after the update so had to delete and reinstall everything to even launch the client.