Why is my Preview app Sidebar not refreshing?

Nope. Pity.

Oooh – this seems to be fixed for me... *fingers crossed*

I spoke too fast. While Safe boot solved it for a few minutes, the bug is back now.

> A SafeBoot Start up your Mac in safe mode - Apple Support will sort many anomalies

Wow, that seems to have solved it for me!

The bug was still there in safe mode, but starting up normally after that I can now work again as I used to.

This is amazing, thank you very much!

manuschwendener.ch wrote:

Same here:

Sorry I can not reproduce the issue on macOS 15.5

To trouble shoot further you can:

 —A SafeBoot Start up your Mac in safe mode - Apple Support will sort many anomalies

Does a quick disk repair before it fully boots up, and certain system caches get cleared and rebuilt, third party system modifications and system accelerations are disabled temporarily.

Login and test. Reboot  as normal and test.  Caches get rebuilt automatically.

This test will tell you if third party interference; most extensions etc are not loaded in safe boot mode. 

—Test issue in another user (or guest user) account Change Users & Groups settings on Mac - Apple Support

 This will tell you if it a universal issue or isolated to your user/admin account. 

***wireless keyboard with rechargeable batteries— connect the charging cable, this will make the wired keyboard successful Safe Boot your Mac.

unplug all non-essential  peripherals when testing

Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus

all known to cause issues on the macOS

Same here:

After deleting a photo in Preview it stil… - Apple Community (unsolved, closed)

After Deleting a Photo in Preview it stil… - Apple Community (unsolved, closed)

Finder Preview thumbnails no correct afte… - Apple Community (unsolved, closed)

> To be proactive you can file a bug report / submit your Apple Feedback here: Product Feedback - Apple

I did, thank you for the link. Preview is not on the list, so I filed it under MacBook Pro.

> my workflow

For people who might want to reproduce this: it often works correctly for the first and sometimes also the second image that I delete, but consistently goes wrong further down.

Describing my workflow, in the hope that it will help to get this fixed.

• I'm out taking pictures
• I copy them from the memory card to a folder on my Mac desktop
• I open the folder, select all photos, open them in Preview
• In the sidebar I see the thumbnails, next to it the bigger version of the photo my cursor is on in the thumbnail column
• The photos I don't want to keep I a) delete in the sidebar, which b) also deletes the image from the folder
• My cursor automatically lands on the next thumbnail, and the next image displays

What is broken now is a)

The image gets deleted, but the thumbnail doesn't. My cursor is now on the thumbnail of the deleted image, the image displayed in big is the next image.

This alone would be wrong, but I wouldn't mind just moving my cursor one image down.

But: moving the cursor to the next thumbnail also loads the next image = the thumbnail is not the same as the image.

So I can't go on with my routine of deleting the superfluous images in Preview.

I have to close Preview and start again from the third point in the bullet list.

Which wouldn't be so bad if there was an alternative with the same basic function – but I haven't found one yet.

> In Quicklook ...

Quicklook has no sidebar with the thumbnails, thus is no help.

> I would recommend changing the Preview >Settings if you have an issue with 'groups'

> "Open each file in its own window"

That removes the sidebar completely, which is no help.