Entity Framework Code First Migration Error

Fixed it by uninstalling and re-installing entity framework. For the benefit of others, here are the commands...

Uninstall:

PM> Uninstall-Package EntityFramework -Force

After uninstalling, reinstall EntityFramework:

PM> Install-Package EntityFramework -Pre

There! It's fixed. Though I still don't know what caused the problem.

I was facing the same issue this is how I solved the issue,

I'm using Visual Studio 2019 and hence I installed latest Entity framework 6.3.0(stable) I was facing the issue when I run the Enable-Migrations command, I tried to re-install the Entity framework but it didn't work so I have installed the old version 6.2.0 from the Nuget package manger apparently it turned out working.

Visual studio 2019: Uninstall-Package EntityFramework -Force

then

Install-Package EntityFramework -Pre -Version 6.2.0

something is up with v6.3.0