I receive the following error when trying to schedule a train to change surfaces:

The mod Subsurface - build beneath your base! (1.1.12) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event Subsurface::on_tick (ID 0)
__Subsurface__/scripts/trains.lua:247: attempt to index field 'stop1' (a nil value)
stack traceback:
__Subsurface__/scripts/trains.lua:247: in function 'handle_subways'
__Subsurface__/control.lua:362: in function <__Subsurface__/control.lua:349>

When manually driving the train it changes surface fine without crashing, but when trying to schedule the train this happens

Can you send me your save game with a train that causes this error?

My save file is linked below:

https://www.dropbox.com/t/Og351o7MBjCy49Na

There are so many mods that the game won't even start. Please remove all unrelated mods from the save.

Try this save. I've removed everything that isn't train related.

https://www.dropbox.com/t/gvuKRPQbeCRoCuG8

Thanks, will be fixed in the next release