NIDmm returns -1074118639 on Init

Hello,

i am executing the generic IVI functions for IviDmm.

For my NI PXI 4070 i installed the NIDMM-Driver.

When executing under TestStand the Init returns 0 and all other DMM functions are working.

But when executing the testplan in a custom GUI then the Init returns -1074118639.

When asking the driver what the error means then it says "Unknown status code".

Does someone now what can be the problem here?

My IviSwtch instruments are working without problems direct in teststand and also under the GUI.

Thanks for all ideas.

BR

Windows 7 64bit

TestStand 2016 f1 32bit

Ni Max 16.0.0.f0

ICP 16.0.1