Validation error when setting up response COARS headers

[mahantaf]

There is problem when setting up COARS headers in a middleware before routes middleware:

app.use(function (req, res, next) {
	res.header('Access-Control-Allow-Origin', '*');
	res.header('Access-Control-Allow-Methods', 'GET, PUT, POST, DELETE, OPTIONS');
	res.header('Access-Control-Allow-Headers', 'Content-Type, Authorization, Content-Length, X-Requested-With, ACCEPT');
	res.header('Access-Control-Allow-Credentials', true);

	//intercepts OPTIONS method
	if ('OPTIONS' === req.method) {
		//respond with 200
		res.sendStatus(200);
	}
	else {
		//move on
		next();
	}
});

require('./routes')(app);

chapar.RPCServer(
	app,
	config.get("connections.chapar")
);

When using Chapar it returns response validation error.
Please consider this and fix it.