Why are my desktop icons not showing a preview of the file?

After hours spent on this today doing some testing, I think I have solved my issue. I was having issues when Airdropping photos. Some of the photos were new ones and some were old, so I think they had different formats. The format was the issue.

If I had "most compatible" selected, 100% of the time when I used airdrop they would show as a blank icon.

If I select "High Efficiency", 100% of the time it would airdrop correctly, showing the icon preview.

It was the setting on the iPhone that was the issue. Now, what I don't understand, is that the format selected has no impact when I Airdrop to my older Mac mini. This issue is an issue only on the Mac mini M4.

I have more feedback for any others that may be interested. I've done a ton of tests and another thing I have found is this... the Highly Efficient works all the time. But as we know, that doesn't always work for other programs so you end up converting to JPEG.

I further found in my testing that the Most Compatible setting, which is JPEG, will not show up correctly for me if I use "keep originals" in the Photos setting for transferring. But if I change it to "Automatic" then the airdropped file comes through as a JPEG and the icon preview works correctly. I don't understand it, I'm just reporting my findings.

Thanks for the response.

I have attempted about 11 times to re-boot into safe mode. I see 'start in safe mode' when I hold down the power button, I hold down shift while it's re-booting, log in, and it seems to never end up in safe mode. I have not yet tried to run first aid under recovery. I may try that but just sharing that, for now, I don't seem to be able to get into safe mode.

For what it's worth, I'm running the same software/apps that I ran on my previous Mac. I transitioned from that Mac to this one.

No antivirus apps.

On cleaning apps, I do have the free version of OnyX on my Mac.

No Security Apps.

VPN: Yes, I have a VPN installed, same one as previous Mac, and it is usually not turned on.

Maintenance apps: OnyX installed as noted.

Not asked about, but I do also have CrashPlan (online backup) and Time Capsule active locally.

I also have 3 external SSDs attached for various Final Cut Pro footage and projects. That is running off a powered hub.

Thank you.

Thanks for the response. I have tried repeatedly and I have been unsuccessful booting into safe mode. Cut unit off, hold power button, select volume, hold shift, boot into safe mode (keep holding shift). Not working. Have tried it repeatedly. Also booted into the same process but selected recovery and ran first aid. No problems there.

I have new info.

When transferring photos from my iPhone (iPhone 15 pro Max) to my computer by airdrop, I will have say 10 pics I took with that phone that will transfer and still look like a white icon in Finder. Then 5 or 10 other taken with the same device will transfer over with no problems (showing correctly in Finder). I don't get it.

Thank for the response.

I have used a private/paid VPN for years. This is new to me that the Mac OS does the same thing. I'm not sure how to use the Mac to provide a VPN. I will have to look into that. I'll gladly take the advice and more just stuck in what seemed to be working. Glad to get rid of an annual fee if the VPN protects my info as the current VPN does. I'll have to play around with it.

I had already connected by keyboard and mouse by cable as there was no other way I could get the "safe mode" to show up.

As another update, I am baffled. I have experimented with the same photo. If I transfer it 10 times from iPhone to my new Mac mini, about 60% of the time it arrives as a white blank desktop icon. The other 40%, it shows as it should. The times when it is white, you can see for like a split seconds that the file does like a really quick preview of the file before going blank. The times when it works as it should, I am doing nothing different. I'm doing these often just back to back. Sometimes it comes through, other times it doesn't. In both cases, I can open the file and view it. Only difference is the icon preview doesn't work in 60% of the cases.

I also noticed that if I transfer the photo by cable to the photo app on the Mac, the file size is larger than if I airdrop it.

No idea why this is not always showing the icon preview.

https://youtu.be/l8amwg-8NYY

I've spent a few hours trying to narrow down this issue. No matter what I do, I can't get it to boot into safe mode even when I think it is going to boot into safe mode. I transferred the same pic to two of my other Macs with no issues.

I went in and turned off various apps that were running in the background upon login. No change.

I made a very quick video of what an image is doing by airdrop. You can see for just like a split second it will show the actual photo in a preview before the screen goes white. What I don't understand is, I can do the same photo 10 times and sometimes it works correctly, most of the time it does not. I can always view it, it's just this icon preview not working.

Thanks for the response, Matti.

To be honest, I "bottomed out" after all that time spent testing different stuff that I've hit pause for now on more testing.

What Mac model are you using?

It is odd to me that I can transfer under both scenarios on my older Mac mini. It appears to be an issue only on this new M4 Mac mini.

I probably won't be able to test this on a cleanly installed volume on another disk without some education on my part, and possible a fresh volume around I can work on. I did transfer my pics to another Mac mini (mentioned above) as well as my wife's MacBook. In both cases I did not have an issue with those systems (both older equipment, but I think at least one is running Sequoia like the new Mac). Only issue on the M4 Mac so far.

I did not try to transfer images from another phone/iPad. Good point. I may try that over the weekend.

Thanks for the response. As part of my process of elimination, I double-checked the updates and saw there was one to run for 15.2. I've been running that during all of the testing. I think the other Mac where mine worked was the same set up yours, the Mac mini 2018 running Sequoia. I'm stumped by it but was relieved when I at least narrowed it down to what I found. I will run more tests over the weekend. I enjoy testing this stuff when I can have an adult beverage at the same time, but too much testing leads to too much drinking. Ha.