When reaching the fallen tree, you're instructed in detail to reverse. The map shows the route to the opposite platform. But the signaller failed to set the points to cross, and the signals are red. When contacted, the signaller replies "no route available". One can actually pass the first red signal (why?) but understandably not the second some 20 yards further. In a facebook post about the same problem, someone suggested "to make sure you hit the marker". But neither an objective nor a stop marker appears after hitting the via-point that triggers the fallen tree (obviously, I enabled the corresponding settings). There's only the instruction to stop and a red signal coming up. There is an additional sound after passing some point and an objective marker appears around there after coming to a halt, but even if these are quite nearby where you stop, the signaller can't be bothered to come to the rescue.
Hey, I had the same problem a few days ago on the Xbox Series X. Look here: https://forums.dovetailgames.com/threads/fife-circle-feedback-thread.80074/page-17#post-1070559 According to the feedback thread, this issue has been around for quite some time. I've given up hope that it will be fixed, just like the faulty sounds on the Class 170.
Thanks. Also, if you search for anything in these forums at the Train Sim World level, it doesn't actually search anywhere. You have to untick "Search this forum only", which means search throughout the entire DTG portfolio (including TS classic, fishing). PS Or rather, press More to switch to advanced search.