Crash occured when added new station after the existing which was turned off by logic. Usually I had schedule: 0-1-0-2-0-3... etc whereas 0 is main and others are to unload. Downloaded this mod to simplify routine to have 0-1-2-3-4 etc.
crashreport:

Error while running event train-station-skip::on_train_changed_state (ID 25)
train-station-skip/control.lua:89: attempt to index upvalue 'circuitCondition' (a nil value)
stack traceback:
train-station-skip/control.lua:89: in function <train-station-skip/control.lua:88>
(...tail calls...)
train-station-skip/control.lua:35: in function 'waitConditionsMet'
train-station-skip/control.lua:8: in function <train-station-skip/control.lua:4>

I got this one when a new train schedule started:

The mod Train Station Skip (0.1.1) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event train-station-skip::on_train_changed_state (ID 25)
train-station-skip/control.lua:89: attempt to index upvalue 'circuitCondition' (a nil value)
stack traceback:
train-station-skip/control.lua:89: in function <train-station-skip/control.lua:88>
(...tail calls...)
train-station-skip/control.lua:35: in function 'waitConditionsMet'
train-station-skip/control.lua:8: in function <train-station-skip/control.lua:4>