Fresh server install says version is older than client?

[DanishD]

Hi, I've litteraly JUST installed a garrysmod dedicated server (via hldsupdatetool), and to be sure, ran it again to make sure it was 100% up to date.

however, when joining immediately afterwards it's started up and running I get a message stating that I cannot join it because the server is running an older version? "the server you are trying to join is running an older version of the game" even though it's a completely fresh installation of it.

I've tried doing this several times, and I still get the message (even after updating the server operating system, win 2008 R2). and my friends can't join it either, getting the same message.

how can this be?