For some reason the VTC HQ is locked so I entered via the sewers. Talked to Castol and got the Dirty Laundry quest. I did what was asked but when I'm going back to the VTC HQ the guards will show me off and it's impossible for me to get to Castol and finish the quest.

 

What to do?

They're closed at night time, if you're trying to go there during the way and getting turned away it sounds like a bug

It's midday according to the clock.

Then it must be a bug.

 

It could be the sewer smell, but if you went to the bathhouse it shouldn't be aproblem anymore.

I can't sneak either so how can I get to Castol? And why is VTC HQ on lockdown?

Somehow this solved it self by restarting the game. So that's good.

Do you have bad reputation with them? If it is not a bug, then I don't see why it would happen. I had -2 with Rauatai and they never let buy in their shops. But I could still visit their buildings.