Access violations and weird uigetfile() behavior

I created a GUI using GUIDE for controlling one output channel of a National Instruments PCI-6722. I'm experiencing seemingly random crashes (Access violation), with no idea how to track down the issue. One particular observation is my uigetfile() function call, which is done in a button callback listener, is sometimes returning immediately without creating a file chooser dialog. The way I am passing data between GUI components is through a single global structure, which can be accessed by both the National Instrument callbacks and the GUIDE callbacks.

Tips on things to try and/or things to look for would be greatly appreciated. I've attached both the .m and .fig files, as well as several crash dumps.

[Sean]

Is there some additional information I can provide that would make this problem easier to diagnose? Are there common mistakes that result in access violations that I can check for?

[Duncan Lilley]

Hello Sean,

Many of the crash logs you provided seem to indicate that the DLL causing the crash is "nidmxfu.dll", which is a National Instruments DLL. I would recommend contacting NI with regards to this crash, as they know their products best.