Finder preview thumbnail not displaying (for JPG, PNG, PDF, etc)

Question

Finder preview thumbnail not displaying (for JPG, PNG, PDF, etc)

Hi all,

For some reason, the thumbnails for documents (images, pdfs, etc.) are no longer showing, and the display is a very generic icon.

I have a Macbook Pro 13-inch, 2018, four thunderbolts 3 ports, running on Mojave Version 10.14.6

I have tried everything and have failed at a solution- list below:

- I have tried deleting com.apple.finder.plist several times, problem persists
- Finder's "show icon preview" is on; I have tried unchecking and re-checking the box, problem persists
- I have created a Test user and downloaded an image- the thumbnail WORKS in the test user
- The main user on my computer has permission to read and write
- I have put my computer in safe mode, problem persists
- Removed apps from launching when booting up Mac, problem persists
- Reset NVRAM, problem persists
- Relaunched preview, problem persists

I've had 2 chats with apple support and 2 phone calls; the final "solution" provided to me was to restore from backup- problem persists.

I'm really frustrated and would love your input on this problem.

Thanks

MacBook Pro 13", OS X 10.11

Posted on Jan 30, 2020 8:04 AM

Reply

Answer 1

Jan 31, 2020 12:10 PM in response to mizzbutterfly

Thank you everyone for all of your help. After days of trying to fix this issue, I have finally found a solution. It appears that it was really my Dropbox finder integration that was causing the noted problems.

I managed to fix this using the following command:

rm -r ~/Library/QuickLook/DropboxQL.qlgenerator
qlmanage -r

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Answer 2

Jan 30, 2020 12:13 PM in response to mizzbutterfly

Here's something from an old thread of a similar issue in 10.13 High Sierra that seems promising:

Quick fix for Quick Look not previewing files - Apple Community

Spend a few minutes googling the issue and see if there's anything else you might come up with.

As always, be sure to have a current backup before mucking about w/ Terminal. =)

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Answer 3

Jan 30, 2020 10:46 AM in response to mizzbutterfly

Try changing the default application associated with opening these images. It should be Preview but maybe that has changed on your machine for some reason.

For example, right-click any .png file and Get Info.

In the file info panel that opens up, select the Open with: triangle, then select Preview as the associated application. Select Change All... and confirm this when prompted.

Now close the file info window and return to your images folder (?) and see if this has resolved the issue.

(A logout/login or restart might be required, but I don't think so.)

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Answer 4

Jan 30, 2020 8:55 AM in response to mizzbutterfly

You've done well with the possible fixes you tried.

Try this: Run Disk Utility and 'First Aid' the internal drive; you may well find the drive directory is corrupted in which case First Aid may well be able to fix it for you. Then report back here!

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Answer 5

Eau Rouge

Level 8

42,656 points

Jan 30, 2020 9:08 AM in response to mizzbutterfly

You said you deleted the com.apple.finder.plist but you didn't say which one, there is one in the main Library/Preferences folder, this one does not store the info for icon previews. Did you delete the on in your Users/<Home>/Library/Preferences folder.

In Finder click on Go in the menubar and select Go To Folder, enter the text,

~/Library/Preferences/com.apple.finder.plist

press Return, move the highlighted file to the Trash and Restart your mac, make sure show icon preview is activated

and see if your icons appear.

The reason I am mentioning this is because you said that the new user account didn't have a problem., so I think it is a problem with User preferences, rather than global mac preferences.

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