Here is a copy of the plugin for UE4.21. Let me know if you all have issues with it. I’ve only tested it for a few minutes. I included the fix from serioussam909, thanks!
https://downloads.metahusk.com/dev/GamepadUMGPlugin_11-18-2018_421.zip
You can find or review the code changes here ->
GitHub - metahusk/UE4GamepadUMG: Unreal Engine 4 gamepad plugin so you can use a gamepad like a mouse in UMG