(Old) Wrath of the Lich King client Error 2136

I really would like to relive the game in pure nostalgia but for some reason the game wont let me log in using the (old) client. I wanted to keep the WoD models out of my gameplay for the full effect.

The download works fine and I get all the way up to the login screen where I type in my account information and then this happens:

It tells me I am unable to connect and then gives me the error number 2136.

However, I am playing the game with the standard client and everything is working. All I am saying is that I would like to switch to the old client and I am wondering if it is a current issue that everyone is having or if it is just me.

Thanks - Mac