Can't get SQL Server CE toolbox to work in Visual Studio 13

Question

I've got a new instance of VS2013 and I'm trying to set up a SQL Server CE instance to test against. I can't seem to even get started. I've installed the SQL Server CE Toolbox plugin, and when I open it all I get is a message that says

The database has been created by an earlier version of SQL Server Compact. Please upgrade using SqlCeEngine.Upgrade() method

What database?

If I try and "Remove Broken Connections" I get a dialog with the same error message. If I try and connect to an existing Northwind.sdf test connection works but when I say "OK" I get a dialog that says "Please tell ErikEJ about this problem"

Answer 1

Rename/delete the files named SqlCe35AddinStore.sdf and SqlCe40AddinStore.sdf located in C:\Users\your name\AppData\Local (%appdata%).

Also make sure you have either SqlCe 4.0 or 3.5 properly installed.

The issue here was that the 3.5 installtion was broken, I will also attempt to improve the check for the precense of 3.5