If you want the newest clantage update you should delete the "clientregister.blob" file in your steam folder.

or:

Completely exit from the Steam client.
Go to C:\Program Files\Steam (or the Steam directory that was specified during installation).
Locate ClientRegistry.blob and rename this file to ClientRegistryOld.blob.
Restart Steam to allow the file to be recreated.
Test the issue once more.

Hello Society,

We want to make the group bigger, so we request every member to invite their friends.

Thanks in advance!