# webExtension can not install Ubuntu Firefox49

**URL:** <https://discourse.mozilla.org/t/webextension-can-not-install-ubuntu-firefox49/11801>\
**Category:** Development\
**Created:** [November 1, 2016, 11:19am UTC](https://discourse.mozilla.org/t/webextension-can-not-install-ubuntu-firefox49/11801 "2016-11-01T11:19:24Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![chnprice](https://avatars.discourse-cdn.com/v4/letter/c/ecb155/32.png) [@chnprice](https://discourse.mozilla.org/u/chnprice)\
**Post date:** [November 1, 2016, 11:19am UTC](https://discourse.mozilla.org/t/webextension-can-not-install-ubuntu-firefox49/11801/1 "2016-11-01T11:19:25Z")

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This user said that he can not install our add-on.  
[https://addons.mozilla.org/ZH-CN/firefox/addon/chnprice-search-for-aliexpress/?src=search](https://addons.mozilla.org/ZH-CN/firefox/addon/chnprice-search-for-aliexpress/?src=search)

Information:  
Ubuntu Firefox49, our add-on verion is newest: 5.2016.1018

 ![](https://us1.discourse-cdn.com/flex001/uploads/mozilla/original/2X/f/f39509dd4530dac270ac9eb2dc0cb4e330679c00.png)

The problem is that once downloaded the plugin button to install does not light up and the installation fails, try and wait ~ 30 mini (tried it on two different computers, it’s not work too). But try to install others add-on, it’s work well.

Please help us.  
Thank you

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**Author:** ![jorgev](https://avatars.discourse-cdn.com/v4/letter/j/71c47a/32.png) [@jorgev](https://discourse.mozilla.org/u/jorgev)\
**Post date:** [November 1, 2016, 7:38pm UTC](https://discourse.mozilla.org/t/webextension-can-not-install-ubuntu-firefox49/11801/2 "2016-11-01T19:38:04Z")

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If the installation failed in some way, the popup should show an error message. It’d be good to check the Browser Console and see if any errors or warnings pop up there.

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**Author:** ![chnprice](https://avatars.discourse-cdn.com/v4/letter/c/ecb155/32.png) [@chnprice](https://discourse.mozilla.org/u/chnprice)\
**Post date:** [November 4, 2016, 11:53am UTC](https://discourse.mozilla.org/t/webextension-can-not-install-ubuntu-firefox49/11801/3 "2016-11-04T11:53:08Z")

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![](https://us1.discourse-cdn.com/flex001/uploads/mozilla/original/2X/0/0334b1eff4230d831f0b09817430bed278b91779.png)

It’s seem not information about it.

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**Author:** ![chnprice](https://avatars.discourse-cdn.com/v4/letter/c/ecb155/32.png) [@chnprice](https://discourse.mozilla.org/u/chnprice)\
**Post date:** [November 9, 2016, 4:12am UTC](https://discourse.mozilla.org/t/webextension-can-not-install-ubuntu-firefox49/11801/4 "2016-11-09T04:12:53Z")

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More and more user report the same problem, and the console panel show not information about.  
Anyone help?

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**Author:** ![NilkasG](https://avatars.discourse-cdn.com/v4/letter/n/0ea827/32.png) [@NilkasG](https://discourse.mozilla.org/u/NilkasG)\
**Post date:** [November 9, 2016, 10:00pm UTC](https://discourse.mozilla.org/t/webextension-can-not-install-ubuntu-firefox49/11801/5 "2016-11-09T22:00:52Z")

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In the current version 5.2016.1018 there is no `"applications"` key in the `manifest.json`. Maybe that’s causing problems.

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**Author:** ![chnprice](https://avatars.discourse-cdn.com/v4/letter/c/ecb155/32.png) [@chnprice](https://discourse.mozilla.org/u/chnprice)\
**Post date:** [November 10, 2016, 4:10am UTC](https://discourse.mozilla.org/t/webextension-can-not-install-ubuntu-firefox49/11801/6 "2016-11-10T04:10:33Z")

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> [@NilkasG](#):
>
> applications

thank you , i will try that.

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**Author:** ![gnappinox1](https://avatars.discourse-cdn.com/v4/letter/g/9dc877/32.png) [@gnappinox1](https://discourse.mozilla.org/u/gnappinox1)\
**Post date:** [November 14, 2016, 3:17pm UTC](https://discourse.mozilla.org/t/webextension-can-not-install-ubuntu-firefox49/11801/7 "2016-11-14T15:17:40Z")

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I have the same problem, here’s what the browser says

```
A promise chain failed to handle a rejection. Did you forget to '.catch', or did you forget to 'return'?
See https://developer.mozilla.org/Mozilla/JavaScript_code_modules/Promise.jsm/Promise

Date: Mon Nov 14 2016 16:02:49 GMT+0100 (CET)
Full Message: TypeError: is not iterable
Full Stack: AddonInstall.prototype.onStopRequest/<@resource://gre/modules/addons/XPIProvider.jsm:5974:1
Handler.prototype.process@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:940:21
this.PromiseWalker.walkerLoop@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:816:7
this.PromiseWalker.scheduleWalkerLoop/<@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:750:11
```

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<div class="post-metadata">

**Author:** ![NilkasG](https://avatars.discourse-cdn.com/v4/letter/n/0ea827/32.png) [@NilkasG](https://discourse.mozilla.org/u/NilkasG)\
**Post date:** [November 14, 2016, 3:54pm UTC](https://discourse.mozilla.org/t/webextension-can-not-install-ubuntu-firefox49/11801/8 "2016-11-14T15:54:00Z")

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The only place I can find code that could cause an `is not iterable` exception is already a promises `.catch` handler.  
Now it would be interesting to know _why_ the previous call to `loadManifest` failed (and did not reject with an Array).  
I’d suggest that somebody who encounters this problem and is interested in the solution opens The browser Toolbox (`Ctrl`+`Shift`+`Alt`+`I` (yet 4 keys)) and sets a cpuple of breakpoints in that function (resource://gre/modules/addons/XPIProvider.jsm:5666) (the line number may be slightly off).