Problem using HW-access in executable

Hello,

i created a C#-DLL to communicate to a DIO-module using modbus (over LAN).

The DLL-functions are called in separate VIs.

Finally this vi´s are called in my GUI and everything runs fine when executing in Developer-Mode.

But after creating an executable of it the DI is not reading anything any more.

What can be the problem here?

After start of the program i run an initialize-vi for the DIO-module that creates a reference as return-value. This reference is saved in a global-VI-variable.

Is it possible that there are problems with global variables in executable?

Thanks for tips