Problem Occurs After Updating Steam
If this problem occurred directly after a Steam update and the firewall is already disabled, please try this process:
Log out and exit Steam
Navigate to C:\Program Files\Steam (the default location). If you have installed Steam to a different folder, please locate that folder now.
Rename the file "ClientRegistry.blob" to ClientRegistryOld.blob and then close the Steam folder
Launch Steam and login. Steam should update, re-create the file, and then you will be able to play
bende bunu buldum yardımlar kısımında deniyorum bakalım ne olacak..