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

I've been having a similar issue. Asked this community, but no answers (Trouble with Preview and Quick Look).

Similarly to Alenem, if I move the files in question to a new folder, the downloads folder, the desktop, or even the trash, image thumbnails and QuickLook work as expected.

I've had this issue since 2 updates prior to Sequoia. I was hopeful that Sequoia would have fixed it, but it didn't.

I regularly move several hundred photos at a time from iPhone to Macbook Air using Airdrop, then transfer them from Downloads to a folder on the desktop. It’s been fine until the Sequoia update but now the thumbnails only display in Downloads. If I move the photos to a new folder (eg on the desktop) some thumbnails are visible, but appear but then disappear, and some only appear as blank boxes, although the photo appears if I double click on the empty thumbnail box and clicking get info shows the full photo size. So it’s just the thumbnail that seems to be an issue. Hoping Apple with fix this quickly.

I’ve got several thousand photos in the Photos app and the thumbnails there are fine.

The issue of missing icon previews began in Ventura, but there was a plist workaround, which offered a temporary fix. However, this workaround was removed in Sonoma, and it appears they have doubled-down in Sequoia. This change significantly impacts my workflow as a long-time Mac designer. They must really want to get rid of us. If any Mac engineers are reading this, unless you want a mass-exodus... DO BETTER!

This is what's happening in Finder - instead of seeing image previews, we are seeing just an icon for the file type. I'm also experiencing the issue since upgrading to Sequoia and noticed it yesterday as I reviewed folders of photographs from an external hard drive. The attached image, however, is from the MacBook Pro hard drive in the downloads folder (on an M1 Pro 16" 2021). Hoping it's fixed soon!

Apple has blocked third-party QuickLook, which is very bad, as there were some for quick viewing of 3D files, the same for other formats, some will have updates from the apps, but for many it will be impossible. Apple takes another step back for professionals...

I reported the issue to Apple at this link: Product Feedback - Apple - there's an option for macOS and I added a link to this discussion so they can see the screenshots, because there's no option to upload one on the feedback form.

It may help if everyone who has posted here reports the issue, too. It would be great to have this fixed sooner than later.

I have the same problem after the Sequoia update. It happened to me only with some PNG files from external drive. If someone doesn't understand what I'm talking about, here's my screenshot, all files should display miniature image preview, but part shows only the standard PNG icon. Already tried copy files, move files, boot in safe mode and nothing helps.

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.

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

Please see Missing QuickLook thumbnail for supported… - Apple Community

I just updated to Sequoia 15.1 and noticed the missing thumbnail issue. It's possible that I haven't waited long enough for the thumbnails to appear in Finder.

A while ago, I wrote an Automator script (see FYI: Generate custom Finder icon for RAW … - Apple Community) to create custom thumbnails for RAW file types that macOS doesn't recognize. The script makes use Adobe DNG Converter and Exiftool. With some work, it would be possible to adapt the script to macOS supported file types. Automator itself can generate thumbnail-sized images for supported file types avoiding the need for DNG Converter.

- Pie Lover

VikingOSX wrote:

In that Finder Window that you just provided a screenshot, press cmd+J to open the Show View Options panel. Is the Show icon preview selected, and if not, by selecting it do the generic icons change to their respective image?

When those PNGs were produced, was there an option to include an icon image that may have been overlooked?

Yes, the option to "show icon preview" is selected on my Mac. This affects - some, not all - image files, including png, jpgs and raw formats and I'm not using any third party viewers. I reported the issue to Product Feedback - Apple

You may want to check in the Activity Monitor to see if the ImageThumbnailExtension process is consuming excessive amounts of CPU. If so, zip (or convert to a DNG with embedded RAW) any RAW files especially ones that were shot with HDR PQ. Finally, either log out and back in or simply Force Quit the ImageThumbnailExtension process.

See Missing QuickLook thumbnail for supported… - Apple Community for more information.

- Pie Lover

It seems that thumbnail creation in Sequoia is performed by a background task (see below). In my case, it is still running so it's hard to tell whether all of my image thumbnails will eventually be restored.

- Pie Lover

I’ve read most of these posts. Everyone is talking about the recent upgrade/update to Sequoia. My 2015 MacBook is running on Monterey 12.7.6, but in the last week or so, the thumbnail images disappeared. So, what would cause that when I haven’t had any updates? I’ve tried JPG, TIF, PSD, nothing works.