Publish: 2024-03-10 | Modify: 2024-03-10
Recently, while developing the Firefox OneNav extension, Xiaoz attempted manual installation of add-ons for debugging. However, an error occurred: "This add-on could not be installed because it has not been verified." Following guidance from ChatGPT, the issue was resolved.
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### Cause
Since Firefox version 48, Mozilla requires all extensions to undergo their validation and be signed for user safety. Unsigned extensions cannot be installed in standard and beta versions, a security measure against malicious extensions.
### Solution
**Method 1: Install via [Firefox Add-ons](https://addons.mozilla.org/zh-CN/firefox/)**
Extensions on Firefox Add-ons are signed after review, avoiding the "not verified" error.
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**Method 2: Use Developer Edition or Nightly**
Install "Firefox Developer Edition" or "Firefox Nightly" as the `xpinstall.signatures.required` parameter is effective only for these versions, not stable or beta versions.
> Firefox download link: [https://www.mozilla.org/en-US/firefox/channel/desktop/](https://www.mozilla.org/en-US/firefox/channel/desktop/)
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Developer Edition offers stable tools for developers, while Nightly showcases the latest developments but with lower stability for testing cutting-edge browser features.
After installation, input `about:config` in the Firefox address bar, agree to enable advanced options.
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Modify `xpinstall.signatures.required` to `false`, then restart the browser.
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Finally, on the add-ons page `about:addons`, install `.zip` or `.xpi` add-ons from file to avoid the mentioned error.
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### Conclusion
For regular users, it's recommended to use Method 1 via [Firefox Add-ons](https://addons.mozilla.org/zh-CN/firefox/). Developers are advised to install Firefox Developer Edition or Nightly and adjust parameters to resolve the issue.
I come from China and I am a freelancer. I specialize in Linux operations, PHP, Golang, and front-end development. I have developed open-source projects such as Zdir, ImgURL, CCAA, and OneNav.