Your terrain file doesnt match the one the server is using.

[DarthVolga]

^^^^^^^^^^^
what do I do?.

[Ad Bot]

[yuki]

It's Self-Explanitory.

Delete your Terrain file, the one that matches the server's.

[Headcrab Zombie]

Delete the one the doesn't match, and you'll download it from the server.

[Starcraftman]

That would only solve the problem for that server you are trying to join. What most likely happened is the host decided to mess with the terrain and saved. Downloading the hosts version of the map would probably make it so you get that error for that map on other servers.

[Headcrab Zombie]

That would only solve the problem for that server you are trying to join. What most likely happened is the host decided to mess with the terrain and saved. Downloading the hosts version of the map would probably make it so you get that error for that map on other servers.

Or he messed with his.

[Starcraftman]

Hmm that actually seems more likely.

[DarthVolga]

So then whats the right thing to do?