Try updating your game.
But it is updated. Isn't that should be 188.8.131.52 version?
If you get a message saying there are no servers available, that is not an error message. There are simply no servers being hosted at that time. AVP Classic 2000 doesn't have dedicated servers. The only servers you will see online are those that are hosted by players at that time.
However, if you get a message that says "Unable to authorize(1)" or something similar, then you need to update your game. Download the latest installation version and install the game again. I had to do this several times over the course of a few months. The newest installer is called: setup_avp_classic_184.108.40.206.exe