"Error! Server verification failed" Problem
This error is caused by the client's inability to communicate with the Secure Master servers to validate the security module being used on secure servers. It can be caused by a few different problems. Here are some things to try:
1) Clients need to communicate with the Secure Master servers (port 27012). First, make sure there isn't a firewall problem.
2) Make sure you do NOT have a file called "woncomm.lst" in your \cstrike folder. If you do, delete it. This file should ONLY reside in your \valve folder.
3) Open the "woncomm.lst" file in your \valve folder (using notepad) and make sure there is an entry that looks like this at the bottom of the file:
4) If your "woncomm.lst" file DOES have the "Secure" entry and you still can't connect to the Secure Master servers, it might be a DNS problem. Try changing your "Secure" entry to look like this:
5) Make sure you have the latest firmware for your router. We've heard reports of people with Linksys 4 port routers having problems and when they updated their firmware the problems disappeared