ask help on the EAL SDK oscilloscope trigger mode

I try to implement the oscilloscope function based on the EAS sdk using c#, everything works fine until I met a question about the oscilloscope trigger

according to the EAL example, I try to set the automatic trigger mode, but come out with a problem, as attached

something like "Parameter: P-0-0026: Invalid operation data"

later, I try to use the executable demo in the example folder, it is the same problem.

But if I try to use the Indraworks DS, everythins works fine.

could anyone give me some advice on this topic? thanks