Hansi Hansi wrote:

What is exactly the error? Which project type you have? What is your entrypoint?

With BOOST_SPIRIT_THREADSAFE defined, the error occurs on startup and is "The application failed to initialize properly (0xc000007b). Click OK to terminate the application." Without that define, the error occurs when trying to parse a file and the error is : Debug Assertion Failed Program: c:\... File: dbgheap.c Line: 1414 Expression: _CrtIsValidHeapPointer(pUserData) The application is a wizard generated C++/CLI Windows Forms app and I am trying to use by class in the Form1_Load function. The entrypoint is main. Thanks, Jason Stewart