I am getting this error when I click on the Twitter login button. It does not redirect to twitter login page.

A critical error has occurred.
Value cannot be null. Parameter name: url

Although everything works fine (I can see twitter login page and after entering the username it redirects back to our public url) on the localhost which is our development environment.

Facebook login works perfect. Appreciate your help.

It works when we try it http://localhost/DNN
It would redirect to Twitter, ask for username and password, etc.
But when we deploy the application on our IIS which has a public URL like http://domain.com/ it doesn't even redirect to Twitter and throws the error i posted previously.
Unfortunately I cannot be more specific about our exact URL in a public forum. please email me at farzan@softsolvers.com.my
We have already used one of our 3 licences for this domain and I don't want it to be a waste. Thank you

Better contact us via the contact us page, making reference to this post url and supply host login. We can then take a look.