I'm trying to install dnn7 locally with the intention to build modules for our custom solution. I downloaded the source code and followed instructions on setting it up, but when I get to the install step it can't connect to the database, even with all the default settings. I also tried setting up a new database in sql2012 to connect it to, but no luck. settings I use are:

Database type: SQL Server Express Database
Server Name: (localdb)v11.0 (I use this to connect in SMSS 2012 express with no problems)
Database Name: dnn_test
Security: User Defined
Username and password are as I set it up in SMSS which I've tested and work
Run database as owner.

I get the error:
ERROR:Index #: 0
Source: .Net SqlClient Data Provider
Class: 20
Number: 53
Message:

with the message field empty...

Am I missing something?