I had the same issue with my (very simple) train line, it was a linear route with loops on the end, and the issue popped up once I added a spur.

Without modifying the route or signals, the train could find a route once I loaded 2.0.10, so perhaps something in there fixed it.

I'm afraid not. I was just playing and building, then the next day my save no longer worked. Unfortunately I'm seeing a similar issue again; I started a new save file and now it won't load either. This time, no crash, but failure to load with a "Notice" screen and the message "Invalid...

This is a vanilla/unmodded installation. Also an issue with [1.1.69] beta. Any time I try to load my save, from either 'continue' or single-player -> load, my game or any of its autosaves, the save loads about 60% then reliably crashes. The logs say Error ElectricEnergySourcePrototype.cpp:57: Energy...