GE Microwave throws E01 error

Randomly our microwave stops immediately after pressing the start button. On the display it show the code E 01. I assume it’s some kind of error code but I have not had any luck deciphering what it means.

After it stops we clear the display and try again. After several tries it will work correctly.

Some days it stops constantly and other days it works fine.

This is a combination microwave on top and oven on bottom unit. The control for the microwave and oven are on the same panel next to the micro wave.

Any ideas on what the code means or how to debug it?

Since I do not have any replies how about some clues on where I can look up the code?