Ken-
I think in order to best answer your question we need additional details about your setup.
First, "mxiFindDevLA" is not an NI function. We provide an operation called "FindDevLA" which is probably related, but it sounds like someone (perhaps an instrument driver?) has provided a new function which may have behaviors we are not expecting. One step that would help us determine what the operation does would be for you to attach the output of NI Spy when your application runs.
Also, I am confused by your side note. FindDevLA (which might be used by mxiFindDevLA) is an NI-VXI API operation. All NI-VXI API operations MUST be run after InitVXIlibrary succeeds. InitVXIlibrary will not work (it will return an error) if there is no controller in your sy
stem. From your side note I can't tell if you have no controller at all, or just some other controller that is not a PCI-MXI-2.
If you can provide this additional information it would assist us in debugging the problem. FindDevLA itself is a simple operation which compares the settings you provide against the device info fields for each logical address in your system. It could cause a crash if you pass in an invalid pointer for the logical address parameter, but that was true in NI-VXI 2.x as well, so I look forward to any additional information you can provide.
-Scot