I got the following error when my game tried to autosave with this mod enabled:

Cannot save map: The mod Trainworks & Couplers (1.0.3) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event ftrainworks::on_save()
Cannot serialise lua functions

I'm not forced back to the main menu, but I cannot save the game at all, even with a manual save.

Funky, I'm not sure why it's trying to do that. I'm rewriting the mod to work better in multiplayer and I'm hopeful that the rewrite will resolve this issue :)

Should be resolved in v1.1.0.