This definitely is a bug with iOS16/High Sierra.
I have experienced the problem as well. I have iOS16 on an iPhone 8 and a mid 2010 iMac running High Sierra.
What I found was that I was able to import JPEG photos, but once I tried to import an HEIC photo, I would get the same error message you have described.
From that point onwards, I could then not import JPEGs either, with error message 9937 now showing the HEIC file replaced by JPEG as in "IMG_xxxx.JPEG (IMG_xxxx.JPEG)". Any future import process was then completely impossible for either file type.
I was able to revert back to successful import of JPEG files by connecting my iPad Air 2 which is running iOS 15.6, and downloading successfully by either importing from iPad in Photos, or ImageCapture. Reconnecting the iPhone then allowed JPEG imports again as well. But try an HEIC file again, and back to the problem of no imports of either file.
I have an 2020 iMac 24" as well, so when I connected the same iPhone which was double file corrupted by the above process in the 2010 iMac, I got the same error messages in the 2020 iMac. Connecting the iPad again, I was able to successfully import a JPEG photo (surprisingly I found that you cannot set the iPad Air 2 to capture in HEIC format, and I suspect this is a limitation of the device rather than the software version).
Reconnected the iPhone, and now the import of both HEIC and JPEG photos was restored. Yay working phone import again!
Summary:
- If you have the iOS16/ High Sierra combination, JPEG import should be OK. If you import HEIC, then neither file can be imported.
- If you can connect a device running an earlier version of iOS, the import function of JPEG's in Photos or ImageCapture can be restored on the device running iOS16.
- It seems the iPhone is "corrupted" in the process as evidenced by getting the same error messages on a newer iMac running a newer version of macOS.
- The iphone can be "corrected" for the newer macOS version iMac however, when procedure 2 is followed.
- As my iMacs are located 80km apart from each other, I have not yet been able to determine whether the same corrected iPhone will again be corrupted in the older iMac running the earlier macOS software. Rather than risk this all again, I have the luxury of time to wait for Apple to recognise this as a bug and possibly provide a fix. This is unlikely if it involves a fix for High Sierra, but most likely if iOS16 is at fault which this new forum topic seems to suggest.
