Add warning for the working directory. Verify win64 fix.
diff --git a/tinyxml2.cpp b/tinyxml2.cpp
index 8ee8ca2..5e5b93d 100644
--- a/tinyxml2.cpp
+++ b/tinyxml2.cpp
@@ -1408,9 +1408,14 @@
 #if defined(_MSC_VER)

 #pragma warning ( pop )

 #endif

-	XMLPrinter stream( fp );

-	Print( &stream );

-	fclose( fp );

+	if ( fp ) {

+		XMLPrinter stream( fp );

+		Print( &stream );

+		fclose( fp );

+	}

+	else {

+		SetError( XML_ERROR_FILE_COULD_NOT_BE_OPENED, filename, 0 );

+	}

 }