"The add-on could not be downloaded because of the connection failure on zotero.org"

hljubinko · November 14, 2014

^This is the notification I get from Firefox every time I try to download the Zotero browser extension for Firefox. I've installed Zotero standalone but I can't start using it without this extension. I've been trying to download the extension for weeks now, but I always get this note, so it's not about some temporary connection problems. Any idea what this is about? My Firefox version is 33.1

dstillman · November 14, 2014

Something (security software, a bad network) is intercepting your secure traffic, and Firefox is actually protecting you.

See Step 5 on https://www.zotero.org/support/kb/ssl_certificate_error and let us know what it says.

hljubinko · November 14, 2014

ok here's the screenshot (sorry the text was mostly not selectable):
http://imagizer.imageshack.us/v2/623x661q90/661/U64AXc.png

adamsmith · November 14, 2014

that looks like Avast inserting itself into your SSL connections, which appears increasingly common for security software, but it's still a bad idea.
If you're using Avast, try temporarily disabling parts of it that seem to directly refer to the browser (I'd expect them to say something about SSL, but hard to say, we've never seen that).

If you're not using Avast, this may point to an infection in your computer.

aurimas · November 14, 2014

That would be Avast Web Shield. There's also a Mail Shield, which seems to be doing the same thing for mail, but it shouldn't be an issue in this case. Still might be worth disabling for troubleshooting.

jeniffur · November 14, 2014

I'm receiving the same error

adamsmith · November 15, 2014

same troubleshooting instructions as above:

See Step 5 on https://www.zotero.org/support/kb/ssl_certificate_error and let us know what it says.

hljubinko · November 15, 2014

that worked, thnx! disable-download-enable-done

aurimas · November 15, 2014

Note that whatever was blocking the download would also prevent automatic updates