Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

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

Èròjà atẹ̀lélànà yii ni a ti fi pamọ́ fọ́jọ́ pípẹ́. Jọ̀wọ́ béèrè ìbéèrè titun bí o bá nílò ìrànwọ́.

How to block extension using policies.json

  • 3 àwọn èsì
  • 0 ní àwọn ìṣòro yìí
  • 776 views
  • Èsì tí ó kẹ́hìn lọ́wọ́ Jonathan

Hi, I planned to block my users from installing extensions/add-ons. I found an article that might be the answer (https://support.mozilla.org/en-US/questions/1308646). I tried to create a simple policy (below), but somehow it does not work (I can still install any add-on/extension). What is wrong with my script? I'm using Firefox ESR 78.11.0 (64-bit) by the way.

My "policies.json" looks like this:

{

"policies": {
  "ExtensionSettings": {
    "*": {
      "blocked_install_message": "Blocked!",
      "install_sources": ["https://addons.mozilla.org/"],
      "installation_mode": "blocked"
    }
  }
}

Sincerely, Jonathan

Hi, I planned to block my users from installing extensions/add-ons. I found an article that might be the answer (https://support.mozilla.org/en-US/questions/1308646). I tried to create a simple policy (below), but somehow it does not work (I can still install any add-on/extension). What is wrong with my script? I'm using Firefox ESR 78.11.0 (64-bit) by the way. My "policies.json" looks like this: { "policies": { "ExtensionSettings": { "*": { "blocked_install_message": "Blocked!", "install_sources": ["https://addons.mozilla.org/"], "installation_mode": "blocked" } } } Sincerely, Jonathan

Ọ̀nà àbáyọ tí a yàn

See:

Note that your curly brackets do not match as you need to add one more '}'. You should see an error on about:policies#errors.

{
 "policies": {
  "ExtensionSettings": {
    "*": {
      "blocked_install_message": "Blocked!",
      "install_sources": ["https://addons.mozilla.org/"],
      "installation_mode": "blocked"
    }
  }.
 }
}

Ka ìdáhùn ni ìṣètò kíkà 👍 0

All Replies (3)

Ọ̀nà àbáyọ Tí a Yàn

See:

Note that your curly brackets do not match as you need to add one more '}'. You should see an error on about:policies#errors.

{
 "policies": {
  "ExtensionSettings": {
    "*": {
      "blocked_install_message": "Blocked!",
      "install_sources": ["https://addons.mozilla.org/"],
      "installation_mode": "blocked"
    }
  }.
 }
}

Cor-El, thank you --- just realized that I missed 1 "}".

Sincerely, Jonathan.