First I would suggest you check out to see if you just need to update the addon. Edit Email Subject seems to have a new release. * EditEmailSubject (Edit email Subject) 3.2 * Works with Thunderbird 68.0 - 69.* * https://addons.thunderbird.net/en-US/thunderbird/addon/edit-email-subject/ * Manually sort folders 2.0.2 * Works with Thunderbird 68.0 - * * https://addons.thunderbird.net/en-US/thunderbird/addon/manually-sort-folders/ Manually sort folders: Suggest you contact the author as they have full responsibility for their addon. There is information about contacting the author at the link to the addon. They may be aware of the issues and a fix is in the pipeline. Or maybe they would appreciate some feedback to know what problems are occuring. Posting in a Thunderbird Help Forum is not contacting those who create the addons. re '':I wish the developers wouldn't turn off compatibility for such extremely attractive add-ons. We need to move forward, not backward! '' I can understand you can get frustrated if you have used some addons that are created by independent people and they do not work. But, you cannot expect Thunderbird developers to cease from maintaining and updating Thunderbird to remain a secure program. Thunderbird has moved forward, it is those who created the addons and choose to not update that have not moved forward. These changes have been discussed for years, so it was well known for a long time that updating would be inevitable at some point. But you also have to respect the wishes of the addon authors if they choose not to update because they do not have either time or inclination or receive sufficient monies to donate time and effort etc. You would not expect an Anti-Virus product not to update so it keeps up with security issues and works with other programs as they make improvements in security. Nothing stands still in the world of security and the internet.

Your points well-taken. Thanks.