What does this mean? In IMovie . Render Frame at Returned. 4 for absolute frame. 22920

As I mentioned in your other post on this issue, the error message is telling you that there is corruption in your project at or around frame 22920. Most likely it is a black frame. So you need to scroll to frame 22920 and scroll around that area and look for signs of corruption, like black frames, white flashes, artifacts. Cut out any that you find and try to re-share. Best to work with a duplicate of your project so as to preserve your original.

Here is a link to a time to frame converter so you can precisely locate the corrupt frame 22920:

https://www.zapstudio.net/framecalc/

You will need the frame rate of your project to enter into the converter in order for it to make the calculation. Then you enter the frame number of 22920. The frame rate of your project will be the frame rate of the very first video clip (not photo) that you placed into the newly created project. The converter will give you the time point in the timeline at which frame 22920 is located. That's the area that you want to scroll around to see if you can find any black frames or other corruption that you can remove.

-- Rich