Hi Rich,
Thank you for your suggestions. I apologize for this belated reply. I've been swamped with other work.
More of my specs:
iMac (Retina 5K, 27-inch, Late 2015), OS 10.11.6 (not willing to upgrade past El Capitan as other vital applications will turn into bricks.
All software up to date (as much as Apple offers updates for this version.) No separate updates available for iTunes, iMovie or anything else.
iPhone Pro Settings - Export was already set to "Automatic," so nothing to change there.
iMovie: V. 10.1.6
All worked fine until just a couple of weeks ago.
All exports result in a Compressor kit failure message.
I tried the suggestion of creating a new user, logging in as that new user, and using iMovie. Two things happened:
1), I was able to create a project but under no circumstances would it allow me to create a new event. I could not drag any video clips into the event window. I did drag video direct into the editing timeline.
2). Tried to output that. Another Compressor Kit error.
I'm intrigued by the other solution you linked to on April 19 at 10:15am.
It suggested running Console, then iMovie, do an export, and see what messages register in Console.
This shows up:
4/22/20 3:25:20.754 PM ProTranscoderTool_sb[21949]: [15:25:20.753] VTRegisterVideoEncoderBundleDirectory signalled err=-12902 (kVTParameterErr) (CFURLRef doesn't point to a directory) at /Library/Caches/com.apple.xbs/Sources/CoreMedia_frameworks/CoreMedia-1731.15.207/Sources/VideoToolbox/VTVideoEncoderSelection.c line 1815
4/22/20 3:25:20.815 PM ProTranscoderTool_sb[21949]: Error loading /Applications/iMovie.app/Contents/PlugIns/Compressor/CompressorKit.bundle/Contents/Frameworks/Compressor.framework/Versions/A/Frameworks/StompUtil.framework/StompUtil: dlopen(/Applications/iMovie.app/Contents/PlugIns/Compressor/CompressorKit.bundle/Contents/Frameworks/Compressor.framework/Versions/A/Frameworks/StompUtil.framework/StompUtil, 265): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice
Referenced from: /System/Library/Frameworks/CoreAudioKit.framework/Versions/A/CoreAudioKit
Reason: no suitable image found. Did find:
/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture
4/22/20 3:25:20.815 PM ProTranscoderTool_sb[21949]: Failed to load ProTranscoder class from NSBundle </Applications/iMovie.app/Contents/PlugIns/Compressor/CompressorKit.bundle/Contents/Frameworks/Compressor.framework/Versions/A/Frameworks/StompUtil.framework> (not yet loaded)
(plus several more lines)
The writer on that other thread found the problem to be the MobileDevice.framework.
He manually force replaced the offending library with a previous version.
I need some instructions on how to do that. Can you help?
Also, he said by replacing that MobileDevice.framework, his iPhoneXR no longer connects to his iTunes. He was willing to live with that.
I am not comfortable with that. I only sync my iPhone11Pro with my iMac by a cable. I do not use wireless synching or backups.