We believe that most of the time this issue is caused by malware on your computer. The malware is modifying Chrome to prevent you from installing any extensions, including AdBlock. Here are two suggestions. Try them in order, proceeding to the next step only if you're still getting the error.


Try this first: Edit your Hosts file

You'll be restarting your computer, so bookmark this page to make it easy to come back to (or print the instructions before you begin).


  1. Follow these instructions from HowToGeek.com to edit your computer's Hosts file in Windows, MacOS, and Linux.
  2. Find the line that looks like this: 127.0.0.1 clients2.google.com 
    Note: If that line isn't in the Hosts file, just close the editing window without saving the file and skip to Reinstall Chrome, below.
  3. Delete that line.
  4. Save the file and close the editing window.
  5. Restart your computer.
  6. Reinstall AdBlock.


Try this if the first suggestion didn't help: Reinstall Chrome

Warning: This step will completely erase your bookmarks, saved passwords, extensions, and Chrome settings on your computer. Before you proceed, be sure to turn on Google Chrome sync and synchronize everything through your Google account!
  1. Uninstall Chrome. Be sure to check Also delete your browsing data.
  2. Reinstall Chrome.
  3. Reinstall AdBlock.


If all else fails, install AdBlock manually


How to install AdBlock in Chrome when you can't do it the normal way.


(Shout out to AdBlock user Tobias S. for pointing us to those HowToGeek.com instructions!)