Know what this is?

[khaotik]

Update issue.
Close STEAM
Please navigate to
C/programfiles/steam/steamapps/yourname/counterstrikesource/cstrike and delete /bin
Move up ONE director (counterstrikesource) and delete /bin. as well.
Now go to C/programfiles/steam/ and delete clientregistry.blob
and appupdatestats.blob

Start steam, let it update.
Now go to steam library-> rightclick counterstrikesource->properties->localfiles->verify integrity of game cache.
Problem will be resolved.
---------------------------------------------------------------------------------------------------------------------
@ anthonyds5.
If someone else if using your account, while you are on it, it will give you this error (this steam id is being used in another location)
OR completely sign you out of steam.