We're having some kind of weird issue with the map version not matching with client side versions and we aren't going to be able to get this fixed by tonight. We're going to have to reschedule all gullywash matches tonight to a later date and hopefully we can fix this issue by tomorrow. I have no idea why a Valve map would be giving people version matching errors so it's a little bizarre; the esea gullywash curse.
Per usual you will have an additional week to reschedule your matches for tonight. Sorry for the inconvenience.