# Can't install my addon from addons.mozilla.org

**URL:** <https://discourse.mozilla.org/t/cant-install-my-addon-from-addons-mozilla-org/6081>\
**Category:** Add-on Support\
**Created:** [December 18, 2015, 5:54pm UTC](https://discourse.mozilla.org/t/cant-install-my-addon-from-addons-mozilla-org/6081 "2015-12-18T17:54:08Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![YujiSoftware](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/yujisoftware/32/3922_2.png) [@YujiSoftware](https://discourse.mozilla.org/u/YujiSoftware)\
**Post date:** [December 18, 2015, 5:54pm UTC](https://discourse.mozilla.org/t/cant-install-my-addon-from-addons-mozilla-org/6081/1 "2015-12-18T17:54:08Z")

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Can’t install my addon from [addons.mozilla.org](http://addons.mozilla.org) .  
[AtCoder Unit Test – Get this Extension for 🦊 Firefox (en-US)](https://addons.mozilla.org/en-US/firefox/addon/ac-unit-test/)

This addon is already Status:Fully Reviewed and Visibility:Listed.  
However, when I click the Add to firefox button, the following message is displayed.  
“Firefox has prevented this site from installing an unverified add-on”

Browser console say…

> 1450459640312 addons.xpi WARN Download of [https://addons.mozilla.org/firefox/downloads/latest/662336/addon-662336-latest.xpi?src=category](https://addons.mozilla.org/firefox/downloads/latest/662336/addon-662336-latest.xpi?src=category) failed: signature is required but missing

But, [Add-on sigined in Firefox](https://support.mozilla.org/en-US/kb/add-on-signing-in-firefox) say…

> All add-ons hosted on [addons.mozilla.org](http://addons.mozilla.org) undergo this process in order to be signed.

How can I solve them?

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**Author:** ![TheOne](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/theone/32/49872_2.png) [@TheOne](https://discourse.mozilla.org/u/TheOne)\
**Post date:** [December 18, 2015, 6:36pm UTC](https://discourse.mozilla.org/t/cant-install-my-addon-from-addons-mozilla-org/6081/2 "2015-12-18T18:36:59Z")

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You were reusing an already reviewed version number, which breaks your file. Please increase the version number and reupload a new version.

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**Author:** ![YujiSoftware](https://sea1.discourse-cdn.com/flex001/user_avatar/discourse.mozilla.org/yujisoftware/32/3922_2.png) [@YujiSoftware](https://discourse.mozilla.org/u/YujiSoftware)\
**Post date:** [December 20, 2015, 4:26pm UTC](https://discourse.mozilla.org/t/cant-install-my-addon-from-addons-mozilla-org/6081/3 "2015-12-20T16:26:27Z")

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Thank you for the advice.  
I will try to re-upload.