Board Thread:Troubleshooting/@comment-2601:442:101:C4F0:A444:7E40:EB1A:C68E-20190723022434/@comment-32823535-20190723024303

That has happened to me. Hasn't happened lately, but I needed to complete a room with the Hoarfrost, and had the blank screen repeatedly, loosing energy AND passes. Try restarting your device. I think that is how I resolved it the last time. I hope that works for you.