While trying to replicate the mentioned bug I ran into another bug. I deleted 7 chars (had 9/12) so I should have 2/12 chars left. However when trying to hire new chars the hire button did nothing and the rosternumber told me I had 9/12 in my company. Re-entering town changed the rosternumber to 2/12 but I still could not hire anything. I do have a log file this time and it shows similar errors as the bug mentioned at the start of this thread.
I accidentily uploaded the log file twice and the save file R15 is not the right one, it’s the save file E15. The E15-after error is the save after the bug happened. Reloading it did not solve the problem, and the game crashed when I pressed the exit game button (see log after crash).
Restarting the game solved the problem. I could load E15-aftercrash and hire new chars.