iMovie doesn't show my photos or videos

Try opening iMovie in the guest account on your Mac and see if iMovie will read the photos there.

If still no luck, try the following procedures:

Resetting the System Management Controller

Try resetting the System Management Controller:

https://support.apple.com/en-us/HT201295

Resetting the NVRAM or PRAM

Try resetting the NVRAM or PRAM, although this issue would be fairly rare:

https://support.apple.com/en-us/HT204063

Contact Apple Support

If neither of the above resolve your issue, contact Apple Support.  The techs there have the capability of remotely accessing your computer that we cannot do here.  To contact apple support click on the Contact Support item in the upper right hand corner of this forum’s screen.  Navigate to a place where you can enter your phone number.

-- Rich

Hi, Anders,

If you have iCloud Photos activated with optimized storage many of your photos and videos may be stored in the cloud and not accessible to iMovie. Try downloading a few and see if they show via the Photos item in the iMovie sidebar.

Also, you can drag the photos and videos from your Photos library to your desktop and from there drag them into iMovie. You might even be able to drag them directly from the Photos library to iMovie. I am not certain whether you would need first to download them into your Photos library.

-- Rich

How long did you wait, Anders? My Photos Library is also an iCloud Photos Library, without "Optimise Mac Storage", so all photos are mirrored locally. But it takes a very long time, several minutes, before the photos will appear in iMovie. For my library with 50000 photos and videos I am seeing "Loading" for ten minutes or so. But eventually the photos will appear. But only the JPEGs, not the HEIC files in my Photos Library, which is very disappointing, since all edited favourites are in the HEIC format.

The problem seems to be, that Photos is no longer creating JPEGs for the Media Browser in since the Big Sur upgrade.So we can only see the files in the Media Browser, that are already JPEGs.

léonie may well have hit on the reason for the problem.

However, try the following procedures to rule out any glitches with iMovie:

Delete preferences. Open iMovie while holding down the Option and Command keys and select to delete preferences in the box that appears. iMovie will open in a new library. Reopen your old library to get back to your projects. See if iMovie will recognize your photos.  Deleting preferences is a safe procedure that will not cause data loss or disruption to your project.

If still no luck, try redownloading iMovie. To update/redownload iMovie 10, drag your iMovie 10 app from the Applications folder into the trash, but do not empty the trash. Sign in to the app store and open your purchases folder by clicking on your name at the bottom of the app store side bar.   You will see your purchases displayed, including iMovie 10. Redownload/update iMovie from there. If not successful, drag your present iMovie app out of the trash and return it to the Applications folder.

-- Rich

😊 Well, I think in this case it was Apple that solved it with an update. But thanks for your kind post.

-- Rich