Trying to setup login for public users using multiple provid

I have been following this document below
www.sitefinity.com/.../working-with-multiple-membership-and-role-providers.aspx

I am developing on my local machine using SQLExpress. I keep receiving a JavaScript error inside the Administration area that says "Response Error 500" after I have fully setup the web.config file. The aspnetdb.mdf file is not being created and I have tried this a couple times and played with the configuration but I keep receiving this error. Is there a updated document to use for this type of configuration. 

Any pointers here would be much appreciated.