No preview for file thumbnails • Mojave

I just renewed my Sketch license, upgraded from 50.2 to 52.1, and can confirm that was the source of the problem on my end at least. If you're a designer and having this issue with Mojave, upgrading Sketch is likely the solution to your problem. Unfortunately, it will cost you if your license is expired. It would be great if the Sketch devs release a free fix for this issue since it's such a deal breaker, but I doubt they would (but who knows!)

Thanks everyone for your input!

I've Sketch installed on my computer and never encountered the problem before. Therefore, I didn't see this problem is related to Sketch. I've performed all the procedures as suggested from the internet, resetting the preferences, checking the disk, but no luck. Then I notice the left disk space on my Mac is low. After I cleaned up more disk space, the thumbnails come back. Therefore, for anyone who has tried everything possible for this issue but is still in no luck, cleaning up more available space on your Mac may be a shot.

I may be burned at the stake for suggesting this (hope not). The Mojave compatible version of Onyx 3.5.0 was just released and you might try running the maintenance routine.

This fixed it for me. Thank you. I tried everything, and updating to Sketch 52 fixed it. Naughty Sketch!

Have you set any of the Adobe suite to be your default image opening application? Get Info may tell the story.

macOS Sierra: Ways to view items in Finder windows

Select Column view options: Change the text size, and whether to display icons and a preview column. All columns display your selected options.

Did you check the disk space on your Mac? It seems the thumbnails take lots of space. If your Mac is out of the disk space then the thumbnails would not be displayed or would be gradually replaced with a default icon.

Hmmm. @Juzmachine may be on to something. I'm a designer and have Sketch installed and it's looking like others are having the same issue, with Sketch being the problem. Of course, I'm on v50.2 and wasn't planning on renewing my license until I have some extra monies in the bank for nice-to-have upgrades. Lovely.

+1. On my computer, only PDF files in non-desktop locations seem to be affected.

Edit: It seems like I get previews if I set my folders to … what's it called in English … grid view? But if I use column view, I only get standard PDF icons.

I have 200 GB of free disk space, I don't have Sketch.

See: My post about Onyx on the first page. Worth a try.

+1

No flames from me.

OnyX is a utility that has been with us for quite a long time (does anyone remember Jaguar...) and it provides a nice GUI for operations you might otherwise do from the command line.

It has nothing to do with the bad lot of apps that are (justly) disparaged here every day. It is a pity to see it sometimes mistakenly accused as if part of that lot.

I have had less and less reason to use it, but always keep it close at hand. Glad to see a new Mojave version is out.

Well, you know how it is around here. One or two people say something negative about an app and then everyone starts repeating it. 😎

I don't use it often but it can be a useful tool. Before the "command + shift + ." shortcut, I was mostly using it to show and hide invisibles. A couple times to rebuild Launch Services. I can never remember the Terminal commands and I'm too lazy to look them up.

I am having a similar issue. Icon previews show inconsistently. Previewing files with the Spacebar won't even function correctly—I just get a spinning loader. Subsequently this happens in any Finder view that also attempts to show a preview of the file. Could this be because I just recently installed Mojave, and Finder is (still) building previews of all the files? And @dialabrain or @Luis, is Onyx known to fix such issues? I do remember using that app but it's been years and years.

Any help is helpful—not having previews is proving to be a real drag on my productivity right now.

This same thing is happening to me and it's not because of sketch. Any new file I save to my computer from anywhere (safari, exported photoshop png's, jpgs, pdfs). I have updated all of the adobe suite so it shouldn't be an incompatibility with adobe programs.