ASP .Net MVC 4, Invalid value for key 'attachdbfilename'

Question

I\'m new to asp.net mvc 4

Below is my connection string

Answer 1

Try changing your connection string to:

Change Data Source to : Data Source=.; or Data Source=.\SQLEXPRESS;

After that, you need to configure access right to App_Data. For Win7, On Security tab in properties Add user network Service with full right.

Found similar question:

asp.net mvc Invalid value for key 'attachdbfilename'

Or in my opinion, it might be just a typo in your connection string. Because you don't have escape character for (LocalDB)\v11.

Try writing Data Source=(LocalDB)\\v11;