Yosemite: Corrupt quick look images

Ever since my transition to 10.10.5 Yosemite, quick look keeps corrupting the preview images every now and then. Sometimes is persists until reboot, other times it goes away after a while. The image files themselves are fine and open and display in any application.

Any ideas?

Example:

enter image description here


Create a guest Account

and test if the problem still persists. To activate the guest account use the following steps:

  • Open System Settings Users & Groups, click on the lock below to unlock it and type your password.
  • On the left panel you see the Guest Account, activate it and log in and test.
  • Deactivate it if you're done.

Repair disk permissions with disk utility

Sometimes files are corrupt and can be repair using the disk utility.

  • Click on the Finder Desktop and then press the keys Command + Shift + G
  • Insert the following path into the small window and hit Enter to open the location:

    /Applications/Utilities/

  • Open Disk Utility and choose on the left panel your System drive.

  • Click on First Aid (El Capitan) or below the buttons check & repair (Yosemite and below) to repair disk permissions. Restart and test if the problem still exists.

Try to reset the quicklook cache

Open Terminal (you find it in the utilities folder - see location above), and type the following commands:

qlmanage -r
qlmanage -r cache

After this is done you need to move some files to your desktop.

Open the following path location and move the files marked bold to your Desktop. Click on the Finder Desktop and press Command + Shift + G and insert the following path in the window:

~/Library/Preferences/

Move the following files to your Desktop:

com.apple.QuickLookDaemon.plist
com.apple.quicklook.ui.helper.plist
com.apple.quicklookconfig.plist

Restart and Test

Check for Hardware Issues

To see if there isn't a Hardware Problem restart your mac and press the D key during startup.


This may help : http://encase-forensic-blog.guidancesoftware.com/2014/05/examination-of-mac-os-x-quick-look.html or https://discussions.apple.com/thread/1289781?tstart=0

You should be able to rebuild the so called ThumbnailCache on your mac. This should work. hope this helps :)