So playing one of the services in Boston Sprinter - MBTA Worcester #521 (Depot - Boston) I follow the correct path for about half of the total distance, signals all fine, and changing points where needed. The path ahead is blue on the map. Until I hit a red signal, which normally would require me to wait - but in this case contacting the signaller tells me "Denied: Your train appears to be off path" - except it isn't, as shown by the screenshot. Any ideas?
The signaller does not need to be contacted in #521. You should enter your block completely so that you do not block the train behind you. The signal will automatically turn green at 16:37:30.
Yes, that was what I assumed the first three times I tried the scenario - I only took this picture to show the blue path ahead, and while I was looking for help the trrain behind moved up. I did actually find the cause of the problem - the train behind me in the image above was stopped very close to an earlier junction that I passed, which looked odd (since all other depot trains that are stationary are backed well into their siding lane). I checked this by jumping into that train and taking over the service, at which point the AI took over #521 and proceeded without issue. So I discovered a workaround, which I'll post here in case anybody else searches: enter the area on foot at 16:20 and go sit in the #521 service. The "stuck" train noted above starts in the correct place, moves off and continues through the junction ahead, not stopping where it does if you load into the #521 service from the timetable. This means it is well out of the way and ahead of you when the #521 service starts at 16:24 and you can proceed to completion without any further issues.
I had that problem for months and I reported it and was trying to figure out what the problem was. That’s great you found a workaround.