why are image thumbnails not displaying in finder since updating to sequoia on my m1 MacBook pro

There is a confirmed problem in Sequoia (15.1) when creating thumbnails for specific image formats (e.g. specific RAW formats from Canon R series cameras). The thumbnail generation process will fail and start consuming excessive CPU. This has been reported to Apple Support and hopefully will be fixed with a future maintenance update.

- Pie Lover

I have a brand new MBP M4 MAX 128GB collected 11 Dec. It's running Sequoia 15.2. My previous MBP M2 MAX had randomly missing thumbnails. The old MBP was transferred across by USBc 3.0 cable to the new MBP on same day.

On 23 Dec I took a session of photos on my iPhone 16 Pro Max. Uploaded them to my target folder 'Camera Uploads'. Some thumbnails created others not (see screenshot 1). Weird. If I double click on the missing thumbnail then a preview of the image shows (see screenshot 2). When I close the preview the thumbnail remains blank.

I have tried deleting various running tasks in Activity Monitor and rebooting. Makes no difference. Tried deleting various cache files (as advised by claude.ai). Makes no difference. Had a session with Apple Chat Support. He had fewer suggestions than claude.ai Waste of time. By the way one suggestion he gave was to reinstall the OS. I'm sure that isn't going to make any difference but it would open up the possibility of losing data and/or having to reinstall applications.

I downloaded Lenscape a third party app from the App Store. Interesting that the missing thumbnails were missing in Lenscape as well.

My conclusion is it has to be an issue with the OS code. And that Apple has failed to fix it. Or has not prioritised it for fixing. But how can you kick a behemoth into action?

If you are a photographer, graphic designer or similar this issue is a real and very major problem for you preventing you from scanning images for selection purposes.

In case this can be useful, below is AppleScript code to modify Show icon preview. The sample code can be edited and included in an Automator workflow (via the run AppleScript action) to process multiple folders.

- Pie Lover

Turn off icon preview

	tell application "Finder"
		
		open (choose folder)
		
		if (current view of front Finder window) is icon view then
			set (shows icon preview of icon view options of front Finder window) to false
		else if (current view of front Finder window) is list view or (current view of front Finder window) is flow view then
			set (shows icon preview of list view options of front Finder window) to false
		else if (current view of front Finder window) is column view then
			set (shows icon preview of column view options of front Finder window) to false
			set (shows icon of column view options of front Finder window) to false
		end if
		
		close front Finder window
		
	end tell

Turn on icon preview

	tell application "Finder"
		
		open (choose folder)
		
		if (current view of front Finder window) is icon view then
			set (shows icon preview of icon view options of front Finder window) to true
		else if (current view of front Finder window) is list view or (current view of front Finder window) is flow view then
			set (shows icon preview of list view options of front Finder window) to true
		else if (current view of front Finder window) is column view then
			set (shows icon preview of column view options of front Finder window) to true
			set (shows icon of column view options of front Finder window) to true
		end if
		
		close front Finder window
		
	end tell

I have the same problem with ios jpg thumbnails showing random blanks when I try to view them on my MacBook air M3 (Mac OS Sequoia 15.3.2). I store my pics on onedrive and the same problem persists. I contacted Apple and Microsoft but got the standard responses which don't work. My workaround is to use XnViewMP app which shows all thumbnails just fine.

I am running 15.0.1. I am having the same issue mostly with PNG files and some Jpeg. I confirmed that it is not the file by copying it to a different older Macbook not running 13.4.1 without issue. Moving file to new location on the same computer does not resolve issue. Quick Actions/Convert Image creates a new file that shows thumbnail. Very frustrating.

I just updated to Sequoia also. Half of my thumbnails (PNG and JPEG) images are no longer showing. If I click one, it does show the image in the preview sidebar. Relaunching finder did not work either.

These files are not in an isolated location. They're everywhere from the downloads, documents, and other folders. They are NOT on my external drives. So it's definitely system based.

My fix: Open in Preview > Save file. Thumbnail shows up again.

Definitely needs a fix!

Sequoia. MBA M3

Select all the non thumbnail files.

Right click - Open with Preview

Cmd A to select all files opened

Cmd R 4x ( Yes I know)

Cmd Q to exit preview.

Note: This works with JPG files. Seems unhappy with PNGs and converts them to JPEG!

Enjoy.

The thumbnails all update for me.

Hope this helps.

See 255833122 for working around the thumbnail issue for CR3 files (especially HDR-PQ images). I also can confirm that the root cause has not been addressed as of Sequoia 15.4.1. My feeling is that this is not a priority for Apple despite the impact to many users.

Also, see FYI: Generate custom Finder icon for RAW images which is the workaround that I've been using since Sequoia 15.1 (when I upgraded from Sonoma).

- Pie Lover

Clicking on one image and Get Info and see what "Open With" shows. On mine it shows Preview.

Update : the problem also disappears when the thumbnail icon size is 192x192...

try changing your icon size value to 80x80 or smaller. It worked out for me..

Same here - jpegs and pngs. What I've tried is opening the image in Photoshop and then saving it as a copy. The new version shows the preview icon and then I delete the one that doesn't. It's not ideal but it seems to work and all of the metadata is preserved.

This also affects HEIC files. Like others, I have some files showing the thumbnail and some not. Also, selecting the ones that don't show a thumbnail and trying to export them in Preview is hit and miss. Sometimes it gives an error that it can't export all the selected files because they're a different type (they're not). I have to do a few at a time and it's just not worth the effort given this number of affected files. I have the same problem with iOS 18. when browsing iCloud Drive folders in the Files app. Some files show the preview and some don't. For clarity, this happens with both iCloud Drive and locally stored files. I think Sequoia and iOS 18 are using the same shared thumbnail renderer, which seems to be broken in the latest version.

Canon RAW is a red herring. Sequoia fails to show thumbnails randomly irrespective of camera type. My thumbnails fail from Nikon and from my Apple iPhone 16 Pro Max 1Tb. The issue is definitely in the importing process. See screenshot which shows images uploaded at the same time from my iP{hone 16 with all images photographed during the same session (when looking at Christmas house light decorations).

If you access the blank thumbnail and rotate it through 360 degrees it solves the problem but doing that for large numbers of blank thumbnails is out of the question. That suggests the code works but randomly fails when importing.

I just updated my MacBook Air M1 to Sequoia 15.5 and every image I save now displays the generic jpeg icon or a blank box as the thumbnail. I've scoured these user sites for answers wasting a lot of valuable time, but had no luck until I read djcaseanova's post here. Open misbehaving file in preview, then export / save to same filename (replace). So far, that seems to work but is a lot of effort. And it flies in the face of Steve Jobs' original intent to make "personal computing accessible to each and every individual so as to help change the way we think, work, learn, and communicate." I find it very disappointing that we're on version 15.5 of this OS and this glaring problem hasn't been fixed yet. Apple, put a team on this and solve it, you're losing loyal customers! (loyal customer since the Mac SE in 1988)