Recently my company require to use Code Review policy from: https://visualstudiogallery.msdn.microsoft.com/045730ee-63c0-498e-b972-42b05a2d0857
The Check-In Tool dialog cannot load that policy with error at policy Warnings:

it is because:

1. It is not registered in Registry.
2. It located at user AppData path folder.

The fix is - add to the registry the key to the located DLL

I implemented that fix at https://github.com/vzabavnov/git-tfs/tree/LocalPolicy. this implementation for 2015 VS only and it also trying to load policy's assembly to the memory before show Check-in tool dialog.

I believe the same issue will be with checkin and rcheckin commands.

Please confirm the issue.