Steam Validation Rejected

So I was wondering, since my hosting service has yet to respond about my ticket on this issue, I was hoping someone here could help me. I have this friend of mine, who tries to connect to my server, but when he does he gets a sending client info bug, so he has to reconnect, but then when he does it says Steam validation rejected, can someone please help?

What game?

Garry’s mod.

We can try to troubleshoot this in a few easy steps.

  1. Windows updated make sure you have them.
  2. Graphics card and GPU updated
  3. Motherboard updated if needed
  4. Shut down your computer and start it back up (nit a restart)
  5. Verify the game cache of Garry’s mod.
  6. Do an antivirus, spyware, and anti rookit scan. I would suggest adware pro.
  7. Make sure all the svn’s are up to date
  8. Run a disk cleanup and a disk defragment of your whole computer
  9. And last shut off steam, go to the steam install directory and delete ClientRegistry.blob and AppUpdateStats.blob empty your recycle bin, restart your computer and start up steam. These are general trouble shoot instructions follow them well.