I have this problem in Thunderbird. I am releasing a Thunderbird ESR 60 compatible version (quickFilters 3.12) and a TB68 version (quickFilters 3.12.1) which are completely different (based on manifest.json) but based on the same code repository. (The main difference is a differen build process and some shim code). Now I got a bug report for quickFilters 3.12 (the Thunderbird 60 version) I just fixed, but I am not allowed to upload it because “You cannot update a WebExtensions add-on with a legacy add-on.” I am not even sure the newer version is a “WebExtension” - is there a workaround? I need to serve my existing users!
