Getting steam validation error when entering games

I go to get into a game, seems to be all pick and when its the first game of the day it happens. I hit accept everyone loads in and it says steam validation error and when i hit proceed and reconnect to the game. pretty much from there my issues are; no cosmetics work in game for me, i can't predict, and i don't even think the game counts. i have no messages from steam on my emails saying anything about this and i don't know where to post this otherwise. i just need some help.