I have been playing with Visual Studio 2015 RC and Entity Framework Code First. In the processes of doing so I ran into this error. Exception calling "LoadFrom" with "1" argument(s): Invalid URL……. This started happening when I upgrade to version 6.1.3. At first I thought this was a file path issue as I also moved where my project was located. That was not it through. I found a couple similar issues doing some searching but the error message was a little different. Visual Studio 2015 RC Entity Framework 6.1.3 Migrations Error Code First Migrations StartUp Project Does Not Reference The Project Contains Migrations The first error I got was about file length, but I had seen that in Visual Studio before so I just moved where my solution was located. Once I moved the location I got this new error about invalid URL. The stackoverflow thread though did point me to a GitHub thread with good info on it. The thing that solved it for me was two things. 1- Downgrad