On Linux (Ubuntu 20.04):
Creating a new game for a second time causes the following error:
$ ./Ambermoon.net
[ALSOFT] (EE) Failed to set real-time priority for thread: Operation not permitted (1)
[ALSOFT] (EE) Failed to set real-time priority for thread: Operation not permitted (1)
Error while preparing game: The given key '9' was not present in the dictionary.
Error creating game: The given key '9' was not present in the dictionary.
$
Update: Opening up the `ambermoon.cfg` file, adding the key `9` and setting it to a random value (no idea what this is for) allows the game the load. Deleting the CFG file also works, but the issue comes back as soon as you try and launch a second time.