Thunderbird 38.4.0 has not yet been released. Reviewing the notes from the status meeting on November 3rd, the release was planned for around November 5th. This delay is not unusual and likely we will be seeing the Thunderbird 38.4.0 release during this coming week.
While going through the meeting notes did notice bug 1211160 which had to do with ‘some’ users who updated to Thunderbird 38.3 with Lightning 4.0.3 enabled lost use of the buttons in Thunderbird. Users reported that rolling back to Thunderbird 38.2.0 resolved the issue. Other uses reported success by disabling Lightning 4.0.3 prior to updating to the Thunderbird 38.3.0 release and then re-enabling lightning. There was an update to Lightning (4.0.3.1) back on October 8th which appeared to be work around for this issue (this did not resolve the issue as the bug is still showing as NEW & Need Info). If you have reverted back to Thunderbird 38.2.0 because of this issue, consider updating to Thunderbird 38.3.0 and then after the restart, update Lighting to the 4.0.3.1 version (does not work with Thunderbird 38.2.0 or older).
As I mentioned above ‘some’ user have had this issue. I did not experience this issue on either my Windows 7 or 8.1 machines when updating to Thunderbird 38.3.0 last month. However, I’ve been running Lightning on those machines when it was still a standalone add-on prior to it being integrated into Thunderbird. I’ve added this bug to the growing list of bugs I am following and will post an update when there is more info.
When 38.3 came out, I updated from 38.2 & 4.0.3. As of today, running an Extensions check for updates reports no new updates – no 4.0.3.1. I also remember running the update 2-3 weeks ago, after Oct. 8th, too. Thanks for the heads up on TB & Lightning issues. Maybe disabling Lightning before upgrades might be a Good Practice from now on. I also experienced no issues as my history with the two mirrors yours, running both looooong before they were integrated. Cheers.
Lightning 4.0.4.1 is not working in Thunderbird 38.4.0. This happened after the automatic Thunderbird update. I cannot see the calendar or task tabs. I have tried deactivating/restarting/activating/ and many combinations but nothing is working. What have I missed, please?
Just update to Lightning 4.0.4.1 with TBird 38.4.0 and everything seems fine.