Hi

If you type about:addons in the address bar and select Extensions from the left hand menu, which add-ons do you have installed?

Hi, Thanks Seburo for your quick reply. I had Avast online security, Avast safe price and Ant video downloader. I removed Ant video downloader and I don't get any notification from avast. May Ant video downloader have cause this issue ?

Hi Ant is just a PUP, Potentially Unwanted Program.

Some programs will key on the fact and others do not as the person has to go through 2 sets of things. 1st is the extension and then the program. I have Ant also. Only 1 of my Anti-Malware Programs finds it.

So yes it is safe, you can put a exception in the rules of Avast if so want to. Unfortunately there was some deceptive Video Down loaders around when Firefox went to 57. So lesser of all evils.

fyi : to keep in mind if have issues with pages : There is security software like Avast/AVG, Kaspersky, BitDefender and ESET that intercept secure connections and send their own certificate.

• https://support.mozilla.org/en-US/kb/secure-connection-failed-error-message#w_avast-and-avg-security-products

Please let us know if this solved your issue or if need further assistance.

I tried to re-install the add-ons Ant video downloader from Mozilla Add-ons website (https://addons.mozilla.org/en-US/firefox/addon/video-downloader-player/) and got again the notification from Avast. I removed it again and downloaded it directly directly from Ant website (https://www.ant.com/video-downloader/versions). Now it works properly. I guess the file from the mozilla website is infected.

Or Avast is just doing false positives which can be the case if you did recent a definitions update.

The https://www.ant.com/video-downloader/versions is just linking to the older version 3.4.57 on https://addons.mozilla.org/firefox/addon/video-downloader-player/versions/