Believe it or not Ed, I have been flying this bird with a broken cooling fin for quite some time. I have at least 30 or so flights on her and in that time and I never had to calibrate the IMU. Because I had not done it in that time, I thought it was time to do it after this last update. That is when the error came up. Thanks to a thread I found here on the forum, I was able to determine the fan vibration was the issue. I guess I have been lucky all those flights.
I stuck my finger in and stopped the fan. IMU calibrated with out a issue. The bird is unbricked now and back in the air. I guess it go's to show you how rock solid the IMU is on the I1 when calibrated correctly. I will still be looking for the fan and get one on the way. I hope that I don't have to remove the light bridge to install. I believe the screws come in from the inside of the LB housing. I will just cut them from the outside and use a adhesive to place back on. I am sure it will be fine. Thanks.