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

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 wish to add here, all of my software produce files that no longer have thumbnails. I have Moho pro 14, Corel Painter, Rhino 7, and CorelDraw that now no longer show thumbnails for their native files within Finder after migrating to a new Mac with OS Seqouia. That would be formats: 3dm, Moho, CDR and RIFF. Hope this helps, thanks in advance

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.

Not a solution. Images are showing previews and thumbnails while others do not. For instance, I take 10 pictures on my iPhone and put them on the Mac.... out of those 10 images 5 or more will not have thumbnails visible. The photos have no difference in settings from the phone, etc. My issue is not just with .PNG files, but .HEIC, .JPG, and all of them are from my phone.

It only is an issue when the images are on my actual Mac hard drive. If I move the images that do not show a thumbnail to an external drive, the thumbnail works just fine. If I move them back to the system's internal drive, the thumbnails don't work again for those same images.

If I open them in Preview or any other software and save them or use the 'convert image' option in Finder, the thumbnails work, but of course the metadata is no longer 100% valid since it's a new file creation (from the system and not the original source).

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.

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.

Now that's strange. Rotated 4 times and no luck. Then rotated once again and they all appeared but were upside down so rotated again and all the thumbnails that were originally blank became blank again. Now that tells me definitively that there is a bug in the code associated with the flag associated with one of the rotation positions. Rotate it and the flag is Ok, rotate it back and the old flag is still there. This is an Apple program bug!!

Anyone know the process for inveigling (by flattery) Apple to fix the bug?

Please see Missing QuickLook thumbnail for supported… - Apple Community

Me too- my post about it:

Thumbnail Views in Folders- Some Are Blank - Apple Community

RyckyP wrote: "...Apple Support pull your finger out and get this resolved."

RyckyP ~ Apple isn't here in these user-to-user communities. Use this form:

Feedback - macOS - Apple

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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

For the case of missing QuickLook thumbnails for RAW image files, see FYI: Generate custom Finder icon for RAW images. This approach uses Adobe DNG Converter and ExifTool to create custom Finder icons for RAW image files (supported by Camera Raw). If interested, please follow the links contained as well as viewing the notes in the set RAW Preview README file.

Finder preferentially displays the custom thumbnail icon in place of the default image icon. I use this approach to workaround a problem related to excessive CPU usage by the macOS ImageThumbnailExtension process for HDR-PQ CR3 (Canon RAW) images (this issue persists in Sequoia 15.3.2).

- 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