Steam auth ticket error 6 issue

[Jerpy]

I was not sure where exactly this should go, but I'm getting this often on my VPS. On my gmod server I'm often getting a mass disconnect with every client on that certain gmod server with it basically saying with each one something like: "Exampleperson disconnected. <Steam auth ticket cancelled (error 6)>" I have no idea what this means and numerous google searches have not cleared this up one bit. It's down until I manually restart it or it 'regains' connection to steam servers which can take anywhere between 2 seconds and 2 hours, I've noticed. I know this has to do with steam servers, and all I have gathered from google searches is that it can usually pertain to windows firewall. Not sure what else to do here, though. Another odd thing is, it only really happens to one of my servers often out of my four. It has happened before on my others, but much more rarely than one in specific. Any ideas?

[kraze]

Steam points to this error being client side but I see it come up here and there for Garry's mod servers due to some type of addon issue. If you disable your servers custom content does the issue go away?

[soja]

I have had this happen to our 64 player CS:S server. It seems random, and I don't think it has happened for a long time now. I never did find the cause, you are probably just going to have to ignore it.

[Jerpy]

Well, interestingly enough, for probably the first time in ever all servers lost connection at the same time all receiving error code 6. All at the same time. They were not able to regain connection so I had to manually restart them. I can confirm that this is not addons causing it. Besides, I think this showed a little bit more of a point today since not all 4 servers have the same addons and it seemed to happen at the same time, which is odd.