Trouble Joining Modded Servers

Whenever I join a modded server, everything loads correctly but when it puts me in the map there is nobody seen in the server, and I cannot spawn a car without it crashing (The servers have like 10+ people too). Is there any way I can fix this, or is this a bug? Thanks!

EDIT: Not sure if this is part of the cause, but it usually says something like “modmanager error invalid zip file” at the top when installing the mods for the server, but it still gets me into the map for some reason but does the same thing as I said above.