Ok, now I know where the problems occur. Now if you could tell me which of the two waypoitn files (see my last post) you have? If you have the old one, I can give you the new one to see if it's any better, and if you have the new one, I know where to look for errors.
However, concerning the vent problem, I fear there isn't really a good solution. I think it's important that Ts can get
onto the roof of that warehouse as well as CTs can enter the building
from the roof - so the connections in that vent must be bidirectional. I could change that and upload a different version for you - however, I guess it still wouldn't fix the problem because even so, two CTs entering the vent right after each other could get stuck forever as well. It's actually more a bot problem...
