If it does take many iterations for the error to occur, then highlight execution may be too slow. Breakpoints will still work. Since the error is thrown by Visual Studio, it's likely one of the calls to the Visual Studio DLL, possibly from the LabWindows/CVI DLLs (based on your original post). I suggest enabling debugging for the DLLs.
Form the LabWindows/CVI Help Manual, there is a page about Debugging DLLs. Verify that the build is in Debug mode. Then, you can set breakpoints within the DLL. LabWindows/CVI needs to be open for the debug mode and breakpoints to work when running the calling LabVIEW code.
Step 5 of this NI Article Writing Win32 Dynamic Link Libraries (DLLs) and Calling Them from LabVIEW says this about debugging Visual Studio DLLs:
"Another troubleshooting option is to try to debug your DLL by using the source level debugger provided with your compiler. In Microsoft Visual C++ 2005, you can set in the Build»Settings»Debug section, Executable for Debug session as labview.exe to debug your DLL. See Using Visual Studio to Debug an Assembly in LabVIEW for detailed instructions about how to troubleshoot an assembly. For even more information on debugging, please refer to the appropriate manual for your compiler."