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

Hierdie gesprek is in die argief. Vra asseblief 'n nuwe vraag as jy hulp nodig het.

Fetching extension fails under MITM proxy even if certificate is added

  • 3 antwoorde
  • 0 hierdie probleem
  • 1 view
  • Laaste antwoord deur GamePlayer

more options

Good afternoon,

I've got a problem with add-ons while using Squid MITM Proxy with a custom certificate for Firefox/LibreWolf.

While I'm trying to update / install an extension / theme, it fails with:

``` 1686147276233 addons.xpi WARN Download of https://addons.mozilla.org/firefox/downloads/file/4104397/witchdoctor-2.0.xpi failed: [Exception... "Certificate issuer is not built-in." nsresult: "0x80004004 (NS_ERROR_ABORT)" location: "JS frame :: resource://gre/modules/CertUtils.sys.mjs :: checkCert :: line 177" data: no] Stack trace: checkCert()@resource://gre/modules/CertUtils.sys.mjs:177 onStopRequest()@resource://gre/modules/addons/XPIInstall.jsm:2514 ```

How can I install an add-on while using the MITM proxy?

Good afternoon, I've got a problem with add-ons while using Squid MITM Proxy with a custom certificate for Firefox/LibreWolf. While I'm trying to update / install an extension / theme, it fails with: ``` 1686147276233 addons.xpi WARN Download of https://addons.mozilla.org/firefox/downloads/file/4104397/witchdoctor-2.0.xpi failed: [Exception... "Certificate issuer is not built-in." nsresult: "0x80004004 (NS_ERROR_ABORT)" location: "JS frame :: resource://gre/modules/CertUtils.sys.mjs :: checkCert :: line 177" data: no] Stack trace: checkCert()@resource://gre/modules/CertUtils.sys.mjs:177 onStopRequest()@resource://gre/modules/addons/XPIInstall.jsm:2514 ``` How can I install an add-on while using the MITM proxy?

All Replies (3)

more options

If the certificate is failing you should contact their customer service support about this issues since that extension is from them. Addon install issues should contact their Developer for support on their Addon.

more options

You can try to download and save the extension's XPI file and install the extension via the about:addons page via the cogwheel menu.

more options

At the moment there's no way to install extension through MITM?