Telescope, SlewToAltAzAsync command failed

[ekempen]

Hello,
My backyard observatory is working fine with ACP Expert Scheduler.
When I run AutoFlat.vbs, flats are taken successfully with no error.

Now I would like to take flats after an imaging session.
When I run "Test Dawn Flats" from the Utility menu in the ACP Expert Scheduler program window,
the following error is displayed in the console output window:

19:53:40 Aiming scope at light source or screen
19:53:40 **Script Error (Tracking has been stopped)**
19:53:40 Source: On_Cue_On_Step
19:53:40 Message: Telescope, SlewToAltAzAsync command failed
19:53:40 Location: line 804 column 13.

It seems like the OnStep ASCOM driver is the problem, but I don't know what is causing the error.

I attached the logfile and my AutoFlatConfig.txt

Kind regards,
Emiel Kempen