You cannot update a WebExtensions add-on with a legacy add-on

(N Athmakuri) #1

while uploading my addon , am getting this error:
You cannot update a WebExtensions add-on with a legacy add-on. Your users would not be able to use your new version because Firefox does not support this type

what can i do ?


See also

(Jorge) #3

Why do you want to revert to a legacy version?

(N Athmakuri) #4

am not revert anything…i want to upload new version


(1) you uploaded version 1.0, which was based on the Add-on SDK
(2) you uploaded version 2.0, which was based on WebExtension
(3) you uploaded version 3.0, which appears to be using the Add-on SDK again

From DaveRo’s link:

In other words: Make sure that version 3.0 in the above example is also a WebExtension Add-on. In case it really/already is a WebExtension, try to figure out what makes AMO think that it isn’t.

I didn’t upgrade my SDK Add-on to WebExtension yet. But it looks like AMO should display a warning when you upload a WebExtension version to a legacy/SDK Add-on the first time: Just to make it abundantly clear that all future versions must also use WebExtension.

(Niklas Gollenstede) #6

I don’t think I got such a warning the first time I performed such an update ~9 month ago, but at least ~3 month ago it did show a very clear warning.

(Jorge) #7

Yes, we did add a warning once we enabled that restriction.

(N Athmakuri) #8

then how can i mention the version… i didnt get it?

(Jorge) #9

You should only see that error if you’re trying to upload a legacy version as an update to a WebExtension, which we don’t allow.

(N Athmakuri) #10

Hi, Could you please help how can i mension the version.
this is my manifest version i have incuded:
“manifest_version”: 3,
“version”: “2.1”,

(Jorge) #11

Please look at the documentation about this:

The manifest version should always be 2

(Frederic Leguen) #12


I’ve got the same error but I just want to submit a new version of my WebExtension with, always, a WebExtension

Only the version of my extension change in the manifest and I made only few corrections in source code.

I have another printed error : “Sorry, we couldn’t load your WebExtension.
Erreur: Validation was unable to complete successfully due to an unexpected error.”

How could I submit a new version of my WebExtension in that case ?


It seems to be a problzm with my zip file that only impact this verification because other tests were ok.
Problem solved with a new zip file.

(N Athmakuri) #13

still am getting legacy addon error:
please check my manifest. whats wrong in this?

“manifest_version”: 2,
“name”: “xxx”,
“short_name” : “xx”,
“version”: “3.0”,
“icons”: { “16”: “images/af_16.png”,
“48”: “images/af_48.png”,
“128”: “images/af_128.png” },

“description”: “xxxxx”,
“homepage_url”: “”,
“permissions”: [

“browser_action”: {
“default_icon”: “icons/af_48.png”,
“default_popup”: “xx.htm”

(Niklas Gollenstede) #14

Does the zip you want to upload contain a install.rdf file?

(N Athmakuri) #15

not having any rdf file…

(Jorge) #16

Can you share the file you’re using?

(N Athmakuri) #17

which file? manifest?


jorge, AMO will accept the upload of a new legacy build for a listed add-on if, only by comparing the number versions, it’s clearly not an update for any later webExtension build? in other words, if the submittion history for the add-on is:

v1.0 (legacy build) --> v2.0 (WE build) --> v2.1 (WE build) --> v1.1 (legacy build, based on v1.0)

The v1.1 will be accepted by AMO and served to users still using 1.0?

(Jorge) #19

I meant the whole XPI.

No, I don’t think AMO will accept that.


Which is why I won’t update to the webextension I wrote a couple of months ago until the Android APIs are available too. Once I release the webextension update for desktop I wouldn’t be able to update the Android version.