VAC System Error

[eu]

Hi, I haven't been playing Insurgency for some months now.
Today I wanted to play the game, so I opened it and pressed 'Quick Connect' to go and play immediately.
This is what appeared:

"An issue with your computer is blocking the VAC system. You cannot play on secure servers.
https://support.steampowered.com/kb_article.php?ref=2117-ILZV-2837.[ "

I tried to go acces this link, and then, again, this appeared:

"Help Desk Error
The specified article does not exist or you do not have permission to view it."


I can play just SOLO on this game now.
Any help please?
Thanks!

[Arc]

https://support.steampowered.com/kb_article.php?ref=2117-ILZV-2837

[eu]

Thanks for the very quick response.
I might go and take a look, and if still doesn't work i'll post here again.