Was working just find last night. I'm assuming ya'll have tried this though. Whenever I get this problem it is when steam or csgo has updated while I'm playing the game. I got that too. Sometime I could play during the night, but I just had to wait till the error disappeared.
So for me there is no fix atm:
Get an ad-free experience with special benefits, and directly support Reddit. This video fixed it for me. It's gonna be like that, probably. Submit a new link. Running steam as an admin seems to be the fix for both of us. Console says "Failed to communicate with routing cluster 'tsnm'.