@caipirinhapilot First, I would suggest that if you're using Windows, then please go to FAF client > top left menu > Settings > Forged Alliance Forever > Use FAF Debugger when starting Forged Alliance > > click "Get the latest version of the debugger". This will create a more detailed log to assist with troubleshooting.
Second, please click the Reply button at the bottom between the (View) icon & the "Mark unread" button. Next, please go to client > top left menu > Show logs folder > logs > sort by Date Modified. From there, drag/drop your most recent game_2xxxxxxx.log file (or whichever was from the last game that crashed due to the observer issue) into the Reply message window so those that can help (not me) have that data to look at.
@Jip Do you know if this issue has been addressed yet?