Since it's not a real support thread maybe we'll share another similar errors we remember, so we know we're talking about the same problem. after map change, or when you try to reconnect after kicked) then your pk3 files are fine. I never looked at the code, but I can fairly say that if it kicks you randomly (i.e. So the reasons why it happens and why the solutions work are so numerous that they probably wouldn't fit in my post.

PK3's' error occured to players almost as always as the 'Server disconnected for unknown reason' error. I've no idea why above solutions work, but the 'Invalid.