What's Happening

Firmware corrupted. More severe than F1E0.

How to Fix It

Reset power. If it returns, replace the board.

Frequently Asked Questions
What does F1E1 mean?
Firmware is corrupted. Board must be replaced.
Difference between F1E0 and F1E1?
F1E0 is memory read error. F1E1 is data corruption. Both need board replacement.
Can a surge cause it?
Yes. Use a surge protector on the oven circuit.