This is getting annoying, I've been getting a Steam Validation Rejected error when I join the first server after getting into the game. I simply just joined a random server first then go the the one I wanted to go to after the error. But now there is a 50% chance for me losing connection to the server 10 seconds after joining and if I try to join again I get the Steam Validation Rejected error. The I have to join a different server, then come back and hope I don't disconnect in the first 10 seconds.
These are the things I've tried that people have said to fix this:
1) Delete ClientRegistry.blob
2) Delete every .dll in the Steam folder
3) Defragment TF2 files
4) Verify integrity of files
5) Installed TF2 dedicated server
6) Added a file called steammapp_id.txt with 440 written in it on the source 2007 dedicated server/tf/ folder
7) Reinstalled game
8) Steps 1 through 4 again
Is there anything else that can fix this that I'm missing? I've done everything that comes up in a Google search