When Safari can't install or update AdBlock or other extensions, AdBlock or other extensions are gone when you open Safari, or AdBlock's settings are reset when you open Safari, it's almost always an issue with Safari, not the extension. This is especially true if the problem is happening with all extensions, not just AdBlock.


Note: If you're installing AdBlock for Mobile on your iPhone or iPad and can't activate the AdBlock Content Blockers, check to make sure you haven't turned on Restrictions.


Error when installing AdBlock or other extensions or your extensions keep disappearing

If you see the following message when you try to install AdBlock in Safari:

Safari can't install this extension
An error occurred while installing the extension "AdBlock".

or you're running into the other issues noted above, there are a few things you can try. Only go on to the next suggestion if the previous one didn't help.


Do a clean install of AdBlock

Yes, we said that most of the time the issue is Safari, not AdBlock. Still, a clean install is worth a try, and it won't hurt anything. If the problem is happening with all extensions, however, you can skip this step.


Try running a script we created to install AdBlock in a way that bypasses Safari's extension manager. We call this a "clean install" because our script uninstalls AdBlock (if it's been installed), then removes files that are supposed to be deleted when AdBlock is uninstalled. Safari sometimes misses these files when an extension is uninstalled, possibly because of a permissions problem. All of this allows AdBlock to install as if it's for the very first time, that is, cleanly.

  1. Download the archive, unzip it, and run the script. (You'll be given a chance to save any work before Safari exits.)
  2. Restart your Mac.
  3. Open Safari.
  4. Reinstall AdBlock from getadblock.com.


Install extensions in Safe Mode

  1. Restart your Mac in Safe Mode by holding the Shift key at startup.
  2. Open Safari.
  3. Reinstall AdBlock from getadblock.com (and any other extensions that keep disappearing).
  4. Restart Safari.


Delete the Safari Extensions folder

Warning: This will uninstall all of your Safari extensions.

  1. Make a note of the extensions you have installed (and any settings you've changed). You'll need to reinstall them later.
  2. Quit Safari.
  3. Go to Finder > Go > Go to Folder.
  4. Type ~/Library/Safari and click Go.
  5. Right-click the Extensions folder and select Move to Trash.
  6. Restart Safari.
  7. Reinstall AdBlock from getadblock.com (and any other extensions you had installed).


Reset the Safari Keychain

Warning: This will uninstall all of your Safari extensions.

  1. Make sure you have administrative access to your Mac.
  2. Make a note of the extensions you have installed (and any settings you've changed). You'll need to reinstall them later.
  3. Quit Safari.
  4. Go to Finder > Applications > Utilities and launch Keychain Access. (Or, open Spotlight Search and start typing "keychain," then select Keychain Access.)
  5. If it's locked, click the lock in the upper left corner and provide your administrator username and password.
  6. Click All items in the Category list on the left.
  7. Enter "safari" in the search box in the upper right corner.
  8. If Safari Extensions List is in the list, right-click it and select Delete.
  9. Quit Keychain Access.
  10. Restart your Mac in Safe Mode by holding the Shift key at startup.
  11. Open Safari.
  12. Reinstall AdBlock from getadblock.com (and any other extensions you had installed).


Clear the cache and preferences

Warning: This will reset all Safari settings, uninstall all extensions, remove all bookmarks, and clear all browsing data. 

You can restore your bookmarks later. Find the Bookmarks.plist file in the folder you moved to the Desktop in Step 3 and drag it into the new ~/Library/Safari folder.

  1. Make a note of the extensions you have installed (and any settings you've changed). You'll need to reinstall them later.
  2. Quit Safari.
  3. Find the ~/Library/Safari folder as above and drag it to the Desktop.
  4. Delete all files in ~/Library/Caches.
  5. Go to the ~/Library/Preferences folder, search for "safari" in the Preferences folder, and delete all the .plist files you find.
  6. Delete the following files:
    ~/Library/Saved Application State/com.apple.Safari.savedState
    ~/Library/Synced Preferences/com.apple.Safari.plist
    ~/Library/Synced Preferences/com.apple.SafariServices.plist
    ~/Library/Preferences/com.apple.WebFoundation.plist
    ~/Library/Preferences/com.apple.WebKit.PluginHost.plist
    ~/Library/Preferences/com.apple.WebKit.PluginProcess.plist
    ~/Library/PubSub/Database
    ~/Library/Preferences/com.apple.internetconfigpriv.plist
  7. Reset the Safari Keychain as above.


Here's a nice article that puts all this together, with pictures!


Turn off FileVault

File Vault can interfere with installing an extension. Make sure it's turned off, then reinstall AdBlock from getadblock.com (and any other extensions that keep disappearing).


Temporarily disable your antivirus

Sometimes antivirus applications can mistake a legitimate software installation for an attempt to install malware. Check your antivirus application's help for how to turn it off temporarily. Then try to install AdBlock. Just remember to turn it back on afterward!


Repair disk permissions (OS X Yosemite and earlier only)

If your Mac's disk permissions aren't what they should be, Safari may not have the right to install extensions. Beginning with OS X El Capitan, file permissions are automatically protected, so this step is not necessary.

  1. Go to Go > Utilities.
  2. Double-click Disk Utility.
  3. Make sure Macintosh HD is selected on the left.
  4. Click the First Aid tab.
  5. Click Repair Disk Permissions.
  6. Restart your Mac in Safe Mode by holding the Shift key at startup.
  7. Open Safari.
  8. Reinstall AdBlock from getadblock.com (and any other extensions that keep disappearing).


Is AdBlock already installed?

You may see a message like this: "An error occurred while installing the extension AdBlock" when you have already installed AdBlock from the Safari extensions gallery and are trying to install it from the file on our website. Check to confirm whether AdBlock is installed.


If all else fails...

If the above suggestions haven't worked, here are two more things to try.


"Install from developer"

Follow the normal procedure to install an extension in Safari, except select "Install from developer" instead of "Install from Gallery."

  1. Visit https://getadblock.com and click Get AdBlock Now!.
  2. Open your Downloads folder and click AdBlock.safariextz.
  3. Click Install from developer.


You'll need to manually update AdBlock. It won't receive updates automatically.


Try this keyboard trick

We (or at least the author of this article) can't explain why this trick works, but it apparently does. Your mileage may vary.


Safari can't update AdBlock

Turn on Safari auto-update

You may have auto-update of extensions turned off. Turn it on in Safari > Preferences > Extensions > Updates.


You can also manually update to the latest version  by reinstalling AdBlock.


Do a clean install of AdBlock

See the instructions above.


By the way, if you have paid for AdBlock and you don't want to do so again when you reinstall it, you don't have to! Just close the payment page when it opens. :)