Has the AdBlock button vanished from the browser toolbar every time you open Chrome? Visit chrome://extensions and see whether AdBlock has been disabled or even uninstalled. Either way, it could be an issue with malware, an extension that doesn't like AdBlock, a broken installation of AdBlock, or even Chrome itself.
Look for malware
If AdBlock is constantly being uninstalled or disabled every time you open Chrome, it could mean your computer is infected with malware—even if you have a Mac. Macs are vulnerable to malware just as Windows computers are, it's just more rare. Malware often looks for and uninstalls extensions that can keep them from doing their nefarious work.
The first thing you should do is check chrome://extensions for any extensions you don't remember installing yourself. If you find any, remove them.
Next, scan your computer with an anti-malware application. We recommend Malwarebytes. We are not affiliated with them; we've just found that their software tends to find malware that others miss. Plus, it's available for both Windows and MacOS, and it's free!
If the scan finds malware, follow the instructions in this Knowledge Base article.
Look for extensions that don't play well with others
If AdBlock is still being disabled or uninstalled when you open Chrome, look for ad blockers that don't want you to use other ad blockers. One that we know about is the Adblocker Project extension. This ad blocker actually uninstalls any others you have. It's no longer available in the Chrome Web Store for this reason. If you still have it, uninstall it.
If you don't have the Adblocker Project extension, here's how to look for a similarly jealous extension:
- Reinstall AdBlock.
- Disable all other extensions except for AdBlock.
- Restart Chrome a few times. If AdBlock is still there each time, it means one of the extensions you disabled is the culprit.
- Enable each of the other extensions one at a time, restarting Chrome after each one, until AdBlock is uninstalled or disabled again. The last extension you enabled is the jealous one.
You'll need to decide which extension you value more, that one or AdBlock. If you like them both, just re-enable AdBlock every time you start Chrome. You can also be a good web citizen by reporting the problem to the developer of the other extension.
Extensions can become corrupted if something goes wrong in Chrome. One indication of a corrupted extension is that its icon in the Chrome toolbar changes to a jigsaw puzzle piece. Chrome disables corrupted extensions. You can visit chrome://extensions and try to repair a corrupted extension, but it's better just to reinstall it.
Chrome also disables extensions when they request new permissions you haven't agreed to allow. Some Chrome updates claim AdBlock needs new permissions and disables AdBlock until you accept them. We don't know what causes this message to appear. AdBlock does not need new permissions. You are perfectly safe in accepting the permissions AdBlock requests and allowing Chrome to re-enable AdBlock.
Have you have accepted the "new" permissions but you still see that notice, and AdBlock is still disabled, every time you start Chrome? Reinstalling AdBlock should fix it.
Try some Chrome troubleshooting
If the above suggestions haven't helped, the culprit may be Chrome itself. Try these troubleshooting steps.