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

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

Solved (for me). Using Sequoia 15.3 this issue happened for the first time using Pages (thumbnail). Came here to find answer - nothing. My solution was to click on 'View' in the Finder menu, open 'Show View Options' and to adjust the thumbnail icon size 'slider'. Alternating from larger to smaller you can watch the generic thumbnail placeholder disappear / reappear as all thumbnails increase / decrease in size. I preferred them larger so left it at increased size and issue is gone. It also seemed to work by going back to original size after adjusting back and forth a few times but I wasn't paying too close attention.

I'm reposting this a from a few days ago :

I'm using Sequoia 15.3.2 on a 14-inch M1 MacBook Pro and I have the same issue with a few jpg pictures files. Adjusting the thumbnail icon size to 80x80 or to smaller sizes has solved the issue for me... The problem seems to appear for icon sizes of 84x84 and up (except for icon size of 192x192, which is huge and non usable for me)..

philip@ wrote:

Solved (for me). Using Sequoia 15.3 this issue happened for the first time using Pages (thumbnail). Came here to find answer - nothing. My solution was to click on 'View' in the Finder menu, open 'Show View Options' and to adjust the thumbnail icon size 'slider'. Alternating from larger to smaller you can watch the generic thumbnail placeholder disappear / reappear as all thumbnails increase / decrease in size. I preferred them larger so left it at increased size and issue is gone. It also seemed to work by going back to original size after adjusting back and forth a few times but I wasn't paying too close attention.

That IS interesting! Yes, for me too, however the only way to get them all to show is at 80x80 sizing. If I increase more and more of the previews disappear. Very interesting development! Thanks! Now if I could just reset all my folders to be 80x80 instead of doing it manually, it'd be good until there's a fix.

I'm using Sequoia 15.3.2 and I have the same issue only for some folders, and only for a few jpg pictures files. Adjusting the thumbnail icon size to 80x80 or to smaller sizes has solved the issue for me... The problem seems to appear for icon sizes of 84x84 and up....

I'm using Sequoia 15.3.2 and I have the same issue only for some folders, and only for a few jpg pictures files. Adjusting the displayed thumbnail icon size to 80x80 or to smaller sizes has solved the issue for me... The problem seems to appear when the thumbnail icon size is 84x84 or larger ...

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.

Apple Support pull your finger out and get this resolved.

Adjusting the thumbnail icon size to 80x80 or to smaller sizes is a workaround to this issue... The problem seems to appear for icon sizes of 84x84 and up (except for icon size of 192x192, which is huge and not really usable (for me).

For me I've isolated the issue down to only images from external sources, cameras and iPhones.

I am running Sequoia 15.2 and using an iPhone 13 Pro Max. Up until Sequoia I had absolutely no issues.

If I take photos on the iPhone and put them on my Mac (usually done via AirDrop), about 25-50% of the images show a white thumbnail afterwards. As shown in other posts, if you click a white thumbnail and have the preview sidebar open the image shows in that sidebar. Double clicking the thumbnail opens up the Preview program and displays the image.

The only way I have found to get my thumbnails to correct so far is to either open Preview (program) by double clicking the thumbnail and saving the image.

OR

Clicking on a thumbnail and going to the sidebar preview pane and clicking '... more' and then "convert image".

However, if I remember correctly, if I move the images with white thumbnails off of the system drives and on to an external drive, I believe that fixes the issue as well. I'd have to double check this once I do another photo dump.

I doubt it is as much as Apple blocking third-party Quick Look code as the software may not have been recompiled to work with the current operating system and any Apple Frameworks that may have changed since the third-party plug-in was originally released. That is on the developer, not Apple.

I used to have a Markdown QL engine that was written several years ago that has not been updated or worked since macOS Big Sur because the original developer never stayed engaged with keeping it current.

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?

I have been looking into this problem for a while, and recently one of my Macs was updated from 15.3.1. to 15.3.2, and the thumbnails all suddenly came back. I still had three other Macs with no thumbnails, I updated the three of them as well, and now all of four Macs are showing thumbnails.

This is usually a preferences updating problem.

Try deleting the com.apple.finder.plist and relaunching the the finder.