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