This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Hierdie gesprek is in die argief. Vra asseblief 'n nuwe vraag as jy hulp nodig het.

Why can't I install AdBlock Plus? I keep getting the message that the signing cannot be verified, but I'm getting the download from the Mozilla site.

more options

I have tried to install AdBlock Plus from the list of Add-ons on Mozilla, but I keep getting a message that the installation was not allowed because signing could not be verified.

I have tried to install AdBlock Plus from the list of Add-ons on Mozilla, but I keep getting a message that the installation was not allowed because signing could not be verified.

All Replies (2)

more options

If its asking about the author verification then you can simply allow and install.

If you have a program called "TDC Digital Signatur" installed on your computer, it may interfere with critical parts of Firefox, including add-on compatibility check, add-on update and Firefox update.

You can try installing it from AdblockPlus website: http://adblockplus.org/en/

This support link might help as well: https://support.mozilla.com/en-US/kb/Unable%20to%20install%20add-ons

Good luck.

more options

Thanks. For some reason, I'm doing all these steps and it's still not working. But I appreciate your suggestions.