After performing a pull from our SCR I got the following error when trying to log into the EPiServer editor.
After a lot of head scratching I figured out the issue was with my VPP folder, specifically the Nuget packages. To fix the issue, first check your .config is pointing to the correct area on your PC where your VPP folder lives, scroll to the bottom of your EPiServerFramework.config and check in the appData section.
After that I had to copy the VPP folder form the UAT site onto my system. When I did my pull nothing came through. After doing this I still got the error, however, after doing an IISRESET and clearing my temp .net files using unlocker everything worked.