my friend istalled BeamNG.drive, opened this, and installed BeamMP, and cant open it. There is a text: ,Primary servers offline…". But on MY computer BeamMP works.
“Primary Servers Offline” is usually thrown when the servers are down on our side, but if you can connect that means that there is some sort of network issue, though I’ve never heard of a network issue populating that particular alarm.
He may need to check to see if his firewall is blocking traffic from BeamMP as described here to fix another issue. "attempting to login" fix!
I have moved your posting into the support topic as well.