I love the Westward Wanderer scenario on the Horseshoe Curve route. Howeve, I am no longer able to get past the Gazatlin tunnel. I get a FATAL BLOWBACK error and the scenario ends. This should happen on a steam loco if you enter a tunnel with the firebox open. These are closed on the K4, because it has an automatic stoke. I tried turning the blower on. No help.
This used to not be an issue, but two things have changed: I'm using TS2014, and secondly, manual fireman. I will try placing the engine before another tunnel and using auto fireman and get back to you!

Down another rabbit hole we go....