I haven’t created or updated a theme since 2017. Apparently there have been changes as to updating and possibly creating themes too. I tried to upload an updated .jpg in a zip file and I got Your add-on failed validation with 1 error. I’m not sure what I did wrong, can someone please advise me.
Also, I don’t have any Android devices, so I didn’t have that box checked. If I knew what size, I’m sure I could make it for that. Does anyone have a template for that?
Thank you for the assistance!
The theme format has recently changed and you now need to include a manifest.json file. The easiest way to get one is to download your theme (right click → “save as”) and then modify the image and re-zip and upload.
As far as I know you don’t provide separate images for android.
You can find documentation on what the manifest can do here: https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/theme - most of these things are also editable with the theme creator from what I understand, but that may only be for the initial upload.
The Create a Theme Version is right below the Upload Version, and works fine to update themes too, and it’s what I’m used to.