Ok, So, it was managed to fix the problem, although not completely. The problem was in the incorrect kits and equipment.
The fix is just replacing this server.zip and mapdata.py in fh2/levels/cmp_berlin_coop folder.
server.zip
mapdata.py
So what I did:I loaded Berlin_64 and _32 maps both in singleplayer and in multiplayer-coop mods. The map loads fine, but when I select any spawn point and confirm, I immediately get the error:
Both FH2 and CMP are updated to the current version.
For example, Tarawa map on the other hand works fine.
ps: seems like I'm not the onlyone who get this error, found few people on reddit with the same issue