Hi guys,
I have found another probable cause for the issue.
Since I am hosting servers for multiple games this is an issue I sometimes encounter:
It is possible port 27000 is already in use.
Avorion needs port 27000, otherwise it wil not connect to the Steam network and you will be stuck to the UDP protocols (which, i think, also cause crashes due to corrupt packets that cause crazy 100% CPU usage).
How do you check this?
Open CMD on your machine (Windows), fill in the following command:
netstat -a -b
This will show a list of all ports that are used and the program that uses it (also listening ports since 27000 is a listening port).
you could output this to Excel or notpad for an easier search (right mouse on CMD, select all, right mouse again and past in Notpad or anywhere else).
Look for port 27000 and the application that uses it, if it's not Avorion, there is your issue.
In my case Garry's MOD was the issue, simply shut down the application that uses that port, make sure to restart Avorion and check if the other application is smart enough to use a different port, otherwise see if you can change the port manualy for that application.