Unable to Create or Play Challenges

When I try to download a challenge or try to create a challenge the game freezes and I keep getting this same error message.

Failed to find AI Behaviour Type:…\src\SIM_Behaviour.cpp 39

If anyone can help with this problem it would be very much appreciated. Thank you.

Have you installed any mods or altered any files? Did you maybe recently let the game patch itself after not playing for months and months?
If thats the case, re-download and reinstall the whole game from the original link, and that should fix it.
Failing that, rename this folder
\my documents\my games\gratuitous space battles
and then put your username and serial number in again

Seems to have fixed itself. Only getting that message on the odd challenge now with most working fine.