When trying to invite a buddy to a 2, 3 or 4 person challenge match, it says that the server is full. I believe that this is due to there being bots filling up the empty slots. How do you reserve slots for friends? Also, if doing a private match it says something to the fact that the server is not found. Any info would be greatly appreciated.

Thank you in advance,

--MarineGeek

I know this error, too.
Steams says that the server is not responding...

Yes, that would be the one. Do you know how to get around it. I joined multiple public matches yesterday, but when I inquired from the people on the server, nobody would respond.

have the same problem here

Agreed. Needs to be resolved. A couple friends and I were going to do the level 2 challenges together to help each other out, but no way to do it effectively as of yet.