Regex y expresión de puntero nulo no válida

I found this website from google and I assume that here people helps with coding problems.

I am creating a badword filter to an application, but I have ran into problems. Currently I am creating a thread from the applications entry point, and the thread flow goes like this:

while(true)
{

    if (!OpenClipboard(NULL))
        ExitProcess(0); //TODO: Try opening clipboard again.

    h = GetClipboardData(CF_TEXT); //h is HANDLE.

    std::string CB_Data = (char*)h;

    if(CB_Data.size() != NULL) //An attempt to check if it's not empty
    {
        if ( std::regex_search(CB_Data.c_str(), BADWORD_FILTER))
        {
            try
            {
                EmptyClipboard();
                SetClipboardData(CF_TEXT, INFORMATION); //INFORMATION is converted to char from HANDLE. INFORMATION = "Bad word filter detected forbidden words pattern."
            }
            catch(...)
            {
                //TODO: Error logging
            }
        }

        else if ( std::regex_search(CB_Data.c_str(), BADWORD_FILTER2))
        {
            try
            {
                EmptyClipboard();
                SetClipboardData(CF_TEXT, INFORMATION); //INFORMATION is converted to char from HANDLE. INFORMATION = "Bad word filter detected forbidden words pattern."
            }
            catch(...)
            {
                //TODO: Error logging
            }
            EmptyClipboard();
            SetClipboardData(CF_TEXT, INFORMATION); //INFORMATION is converted to char from HANDLE. INFORMATION = "Bad word filter detected forbidden words pattern."
        }
    }

    CloseClipboard();
    Sleep(1000); //Check every 1 second for the forbidden words.
}

So this application monitors clipboard from forbidden words. However, most of the time I run into an "Expression: Invalid null pointed" -error, and I am not familiar with Visual Studio debugger. I tried, but obviously didn't success very well.

Aquí está el error: http://i.stack.imgur.com/wACnA.png

Cualquier ayuda será enormemente apreciada, gracias.