Error while opening Hammer in Source SDK using Source Engine 2009)

I tried to open hammer on Source Engine 2009 on Episode 2, but heres the error that came up:
“MountFilesystem ( 305 ) Failed:
SteamMountFilesystem(6076,305,0xbacfd28=,0xbacfc18) failed with
error 5: No Steam Content Servers are available”

Can this be fixed or is this one of the problems Valve his to fix on their own?

I had this too. I verified HL2 and EP2 and restarted steam and it seemed to fix it.

Then again maybe there was a tiny update, :iiam: