I'm using Photos to organize my photos since it came out. However, since the Sierra upgrade, the thumbnails for many of my photos are showing as missing:

Missing thumbnails in Photos. Thumbnails have a light gray background with a dark gray triangle containing an exclamation mark.

Most of the photos do not show properly when double-clicked, but going back and forth between the photo display and the photo editing tools seems to sometimes get them back.

This seems to happen indiscriminately with iPhone photos and Canon RAW photos. In addition, some thumbnails are purely associated with the wrong photos:

GIF showing a double-click on a photo thumbnail that expands to a completely different photo.

How can I make my thumbnails come back? Is there any risk of losing the photos themselves?


2 Answers 2


Try repairing your Photos library. You can do this by holding down the keys Command + Option when launching Photos.app.

macOS Photos - Repair Library dialog

  • Every photo in my latest album disappeared from my library after repairing it. Fortunately, the originals are still in the Photos library bundle and I could get them back, but I lost my edits. You don't deserve any blame for it but I'll leave it out there that this is a possibility. I haven't verified yet that the issue isn't coming back, I'll look at it tomorrow.
    – zneak
    Oct 4, 2016 at 7:48
  • That is terrible! I am sorry to hear the repair caused problems! Please can you report this directly to Apple as data loss should be impossible. Be sure to back up all you can now while you have the opportunity; who knows what underlying problem may yet be lurking. Oct 4, 2016 at 7:54

This may be a possible solution:

  1. Open your Photos App
  2. Click on Photos (in sidebar on the left)
  3. Select one thumbnail and then press Command+a, in order to select all photos at once
  4. After having selected all photos, right click, and click on Rotate.
  5. This will take a while depending on the amount of photos you have.
  6. After it has rotated all the photos, select all the photos again, and click on Rotate anti-clockwise, (to get the thumbnails rotated back to normal)
  7. This should solve your issue!! i.e. this is a workaround to rebuilt your thumbnails.


Do not use cleanup software such as CleanMyMac, especially not for Photos at least. This is the most probable cause to destroying the thumbnails.

  • 1
    I don't use cleanup software. Also, see edit–in my case, even after this manipulation, some photos just have the wrong thumbnail.
    – zneak
    Oct 7, 2016 at 6:09

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