Thunderbird Themes

What happened to all the themes on the Thunderbird site? Now there only seems to be a relatively small number.

They haven’t been converted to Web Extension themes is my conclusion.

Theme support: Only WebExtension themes are supported now. Both addons.mozilla.org and addons.thunderbird.net now provide WebExtension themes.

REF: Thunderbird 68.0 Release Notes

Can you explain what “WebExtension” themes means or are?

What does “WebExtension” mean?

See About Add-ons and Browser Extensions.

I have been trying to submit some of my themes that will work with the latest Thunderbird and it is almost impossible. Actually so far for me it IS impossible. I can get it to pass all the checkmarks.

Now I can’t even sign in to the account. I keep clicking on send email and it never sends it! Frustration is the name of the day!