Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

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

How do I install an unsigned addon on the Developer edition?

  • 7 replies
  • 2 have this problem
  • 1 view
  • Last reply by cor-el

more options

I want to install an unsigned addon that I made. I can load it temporarily via about:debugging, but I can't actually install it. Maybe I'm doing it wrong, I couldn't actually find any explicit instructions online, so I packed the files into a zip with a .xpi extension, and tried dragging it into the about:addons page. I get a "the addon could not be installed because it appears to be corrupt" error.

After reading this thread: https://support.mozilla.org/en-US/questions/1134589, I went and installed the developer version of Firefox Quantum, but I'm having the same problem.

I want to install an unsigned addon that I made. I can load it temporarily via about:debugging, but I can't actually install it. Maybe I'm doing it wrong, I couldn't actually find any explicit instructions online, so I packed the files into a zip with a .xpi extension, and tried dragging it into the about:addons page. I get a "the addon could not be installed because it appears to be corrupt" error. After reading this thread: https://support.mozilla.org/en-US/questions/1134589, I went and installed the developer version of Firefox Quantum, but I'm having the same problem.

Chosen solution

I just solved my own problem.

It occurred to me that Firefox probably logs more details about the "addon was corrupt" error in the Browser console (Ctrl + J), so I opened that, and there it was:

1519080608004 addons.xpi WARN Invalid XPI: Error: Cannot find id for addon C:\Users\Jack\Documents\WebExtensions\NoHistory\NoHistory.xpi (resource://gre/modules/addons/XPIInstall.jsm:1603:17) JS Stack trace: loadManifest@XPIInstall.jsm:1603:17

So the problem was the lack of id in manifest.json . For anyone else with this problem, also remember that the id needs to be formatted like an e-mail address.

So in summary, the process is:

1. Grab all the files for your WebExtension and package them directly (not in a folder) in an uncompressed zip.

2. Replace the .zip extension with .xpi.

3. Drag the XPI into Firefox's about:addons page.

4. If an error appears, check the browser console (Ctrl + J). Maybe open the console first and then load the extension, just in case.

5. (EDIT) At least on Linux, I also had to go into about:config and change the xpinstall.signatures.required parameter to "false".

Read this answer in context 👍 0

All Replies (7)

more options

This seems to indicate it is corrupted or doesn't meet the FF57+ requirements to install properly. You should ask Mozilla debug support what else is causing the corrupt install.

more options

Where can I contact debug support?

more options

Is this about a Legacy extension or about a WebExtension?

What is the folder structure in the XPI (ZIP) archive?

The install.rdf file and the chrome.manifest file needs to be in the root level. If you packed a directory and not the individual files then the root level might be a folder.

more options

It's a WebExtension.

I've never actually heard of an install.rdf file. All I have other than scripts and images is manifest.json . I'm honestly working off of guesswork here because I couldn't find explicit instructions on how to do this - the closest I could find is this page, but it doesn't mention install.rdf .

The ZIP file contains the files directly, ie they're not in any subfolders within the ZIP.

Weirdly, I was able to package and install a different addon that I developed, using the same process.

more options

Chosen Solution

I just solved my own problem.

It occurred to me that Firefox probably logs more details about the "addon was corrupt" error in the Browser console (Ctrl + J), so I opened that, and there it was:

1519080608004 addons.xpi WARN Invalid XPI: Error: Cannot find id for addon C:\Users\Jack\Documents\WebExtensions\NoHistory\NoHistory.xpi (resource://gre/modules/addons/XPIInstall.jsm:1603:17) JS Stack trace: loadManifest@XPIInstall.jsm:1603:17

So the problem was the lack of id in manifest.json . For anyone else with this problem, also remember that the id needs to be formatted like an e-mail address.

So in summary, the process is:

1. Grab all the files for your WebExtension and package them directly (not in a folder) in an uncompressed zip.

2. Replace the .zip extension with .xpi.

3. Drag the XPI into Firefox's about:addons page.

4. If an error appears, check the browser console (Ctrl + J). Maybe open the console first and then load the extension, just in case.

5. (EDIT) At least on Linux, I also had to go into about:config and change the xpinstall.signatures.required parameter to "false".

Modified by Gaiajack

more options

A forum to ask for Extensions help is in https://discourse.mozilla.org/c/add-ons and a secondary place is on the independent mozillaZine forum http://forums.mozillazine.org/viewforum.php?f=19 if you have an account there.

more options