FileStorage::READ runtime exception

edit

I am using OpenCV 2.4.6 with VS2012 c++/cli in Windows 8 and trying to simply read a matrix from a file. At runtime, I am crashing when I try and open the file and I am getting an error saying "System.Runtime.InteropServices.SEHException" - "External component has thrown an exception".

I have two questions: 1) what is causing this error; and 2) why is try/catch not handling this error?

My code looks like:

private: System::Void buttonLoadStyle_Click(System::Object^  sender, System::EventArgs^  e) {
    FileStorage fs;
    try
    {
        fs.open("SVStyle0.xml",FileStorage::READ);
    }
    catch(cv::Exception& e)
    {
        const char * err_msg = e.what();
    }
    catch(...)
    {
        System::Windows::Forms::MessageBox::Show("Load Style Exception","Rune Time Error!",MessageBoxButtons::OK,MessageBoxIcon::Error);
    }

    if(fs.isOpened())
    {
        // do something
    }
};

I get the exception when the the fs.open line tries to open the file. Further, the exception is not caught by my try/catch blocks.

Edit: When I remove the ".xml" extension, I execute past the fs.open line but, of course, do not find the file. Seems like it might be something with parsing the filename.

Any help greatly appreciated. Thanks