My save file and logs are attached! No mods used in this game.70.581 Error Train.cpp:698: this->signalLogic.matchesTrainPath(const_cast<Train*>(this)->getEndByMovement().getRail(), this->path) was not true
The two previous autosaves also wouldn't load, but thankfully the third autosave does so I'll only lose 15 minutes!
I think it may triggered by this intersection I have at the North end of my Eastern base:
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Those rails are too close together, so the circled chain signal has become a blinking "error" signal in the new 0.17.50 version.