Hmmm, so I carefully ensured that I met the requirements and had the right package for my model 224113, I restored a stock TMO twrp backup, and ran rumrunner.
All seemed well until suddenly I encountered the following error during test 3
FATAL: **** IT
Now it's been printing periods in the cmd window for about 15 minutes.
The device is in bootloader.
What is safe for me to do?