CLONER: 404 error when duplicating

The requested URL /wp-admin/ was not found on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

The error shows up when I try to clone my blog ( I need to rebuild) at enduringepilepsy.com to where I would like a staging site (currently blank) at staging.enduringepilepsy.com

I just enabled multisite tonight and was following the guide here for using cloner to set up staging but when I get to the point where it says "Next, Cloner will try to keep you from making a mistake" and try to proceed, I can't.

How do I get rid of this error so I can have my staging site? I've enable access for support.