I get this error when I try to change the steps/tick number both in the settings and while it is running.

The mod Automatic Belt Planner (0.13.9) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event beltplanner-patched-18::on_gui_text_changed (ID 2)
beltplanner-patched-18/control.lua:660: bad argument #1 of 2 to 'newindex' (string expected, got number)
stack traceback:
[C]: in function '__newindex'
__beltplanner-patched-18/control.lua:660: in function <beltplanner-patched-18/control.lua:643>

any number? or or specific numbers?

Nevermind i found and fixed it

Die Mod Automatic Belt Planner (0.13.10) hat einen Fehler verursacht, der nicht behoben werden kann.
Bitte informiere den Autor der Mod über diesen Fehler.

Error while running event beltplanner-patched-18::beltplanner_abort (ID 170)
beltplanner-patched-18/control.lua:703: attempt to index field 'beltplanner_gui' (a nil value)
stack traceback:
beltplanner-patched-18/control.lua:703: in function <beltplanner-patched-18/control.lua:673>

When does this crash happen?

The bug usually appears during the planning phase.

So when the start and end points are set and he calculates the path.

I'll pay more attention to it in the future and let you know.