The Lightning calendar extension is distributed bundled with Thunderbird release versions for several releases now. Over the time, users have been experiencing different update issue related to Lightning. If the Lightning update didn't run smoothly for you, you might find your issue and a recommendation how to deal with it listed below. The described solutions should apply to all versions of Thunderbird starting with Thunderbird 38, if not marked otherwise. If you are using Linux and installed Thunderbird and/or Lightning by using the package manager of your distribution, then these how-tos are not applicable - please contact the support of your Linux distribution to get help. In general, these instructions apply to Seamonkey, however, details of the steps to resolve might be different. =Lightning disappears after a Thunderbird update (release and beta versions)= This may happen if the update of the add-on is stuck for whatever reason. Don't worry about your calendar data, it is left untouched and will be available again if you follow these steps to restore Lightning: # Go to the {menu Advanced} section of Thunderbird [[Template:optionsorpreferences]] and click on {button Config Editor...} # Copy or start typing {pref extensions.installedDistroAddon.{e2fda1a4-762b-4020-b5ad-a41df1933103}} into the search box # When it is listed in the preferences list below, right-click on it and choose {menu Reset} from the context menu - the preference now isn't bold anymore and its value is empty # Close the editor, leave the Thunderbird options, open Thunderbird's add-ons manager and switch to the list of installed extensions # If Lightning is listed there, click on {button Uninstall} to the right of the list item # Restart Thunderbird After Thunderbird has been relaunched, Lightning will be back and you will have access to your calendar data again. =Lightning disappears after a Thunderbird update from 52.* to 60.* on Ubuntu (and possibly other Linux flavors)= This may happen if you originally installed the Lightning add-on via Thunderbird's add-on manager and hence from [https://addons.mozilla.org Mozilla Addons Site (AMO)], as opposed to the Linux Distribution's package manager, which is a rather recent possibility. In this case, upon updating Thunderbird from version 52.* to 60.* with the package manager, only Thunderbird gets updated, as only this package is installed. The Thunderbird add-on {pref Lightning} from AMO gets disabled as it's not compatible with Thunderbird 60.*, and there is no newer add-on version available on AMO nor the new [https://addons.thunderbird.net ATN site]. Unfortunately, they apparently forgot to consider this case when preparing the Ubuntu package of the new Thunderbird version, and hence Lightning doesn't get installed automatically as a dependency. How to fix: # In your package manager (e.g. {pref Synaptic} in Ubuntu, or {pref apt}, {pref aptitude}, ...), downgrade Thunderbird back to the latest available 52.* version via {button Force Version}. # Back in Thunderbird 52.*, the calendars should be back for now. # Install the following additional packages via the Linux package manager, equally forcing their version on the latest corresponding 52.* Thunderbird version: {pref xul-ext-lightning}, {pref xul-ext-calendar-timezones}, {pref xul-ext-gdata-provider} # Restart Thunderbird, the calendars should still be there. Now, in Thunderbird's add-on manager, remove the {pref Lightning} extension (version 5.4). This removes the one version, and should provoke Thunderbird to use the installed version from the Linux sources, instead. # Restart Thunderbird again. Your calendars should still be there. Also, in Thunderbird's add-on manager, {pref Lightning} should still be listed, but there is no button to {button remove} it anymore, only to {button disable} it. It might happen that you'd have to re-activate a master password (if you had any) and re-enter all your passwords for all mail and calendar accounts as upon un-installing the {pref Lightning} extension in the previous step, for some reason Thunderbird might flush its {menu Password Manager} settings. # In Linux' package manager, upgrade Thunderbird and its related packages to their current 60.* version. These are same packages you installed purposefully in step 3: {pref xul-ext-lightning}, {pref xul-ext-calendar-timezones}, {pref xul-ext-gdata-provider} # Restart Thunderbird once again. You should be running Thunderbird in the latest version now, and with the calendars back and active. It might even work for you, after upgrading Thunderbird to 60.* and being left without calendars, to simply install the above packages. However, in case this alone doesn't bring back your calendars, the way described above should work. =Lightning reappears after a Thunderbird update although I opted out (release and beta versions)= If Lightning shows up for you again after a Thunderbird update and you don't want to have it, uninstall it: # Open Thunderbird's add-ons manager and switch to the list of your installed extensions # Click on the {button Uninstall} to the right of the Lightning list item # Restart Thunderbird This will stop bringing back Lightning after a Thunderbird update. If you change your mind in future, simply follow the instructions to restore a missing Lightning above (while leaving out steps 4 and 5). =After a Thunderbird update, the first day of the week in the calendar views is set to Sunday= This is related to a cross update from a bundled version to a version from [https://addons.thunderbird.net ATN] (formerly [https://addons.mozilla.org AMO]) add-ons distribution platform and cannot be avoided technically at the moment. '''Thunderbird 60.0 has a bug at the moment, that makes this issue appear regardless of the previous update channel.''' If you encounter this issue, please reset the first day in a week to your needs: # Open the {menu Calendar} section in Thunderbird [[Template:optionsorpreferences]] and switch to the {menu Views} tab # Select in the {menu Start the week on} dropdown menu whatever is right for you Unfortunately, this might occur again if you run in the same update scenario in the future. If so, please correct the settings as described before. The Lightning and Thunderbird team tries to avoid this by distributing Lightning updates bundled with Thunderbird, for which this is not an issue. =When I use my user profile from a previous Thunderbird version with a newer version of Thunderbird, Lightning is not updated= If you are downloading a newer Thunderbird version instead of waiting for the automatic update or e.g. you want to test something it a beta version and you don't want to setup everything from scratch, you could use a previously used user profile. When doing so, the Lightning version should be updated when starting the Thunderbird with that profile. If it doesn't, then resetting will help - this doesn't affect your calendar data. # Start Thunderbird with the selected user profile # Go to the {menu Advanced} section of Thunderbird [[Template:optionsorpreferences]] and click on {button Config Editor...} # Copy or start typing {pref extensions.installedDistroAddon.{e2fda1a4-762b-4020-b5ad-a41df1933103}} into the search box # When it is listed in the preferences list below, right-click on it and choose {menu Reset} from the context menu - the preference now isn't bold anymore and its value is empty # Restart Thunderbird N.B.: if you do this e.g. for testing a beta version, and you want to continue to use that copy of the [[Profiles - Where Thunderbird stores your messages and other user data|profile]] on a previous version of Thunderbird afterwards, you eventually would have to do the same procedure on that Thunderbird version again. Therefore for beta testing it is recommended to [[Using Multiple Profiles|use a separate (copy of the) user profile]].

The Lightning calendar extension is distributed bundled with Thunderbird release versions for several releases now.

Over the time, users have been experiencing different update issue related to Lightning. If the Lightning update didn't run smoothly for you, you might find your issue and a recommendation how to deal with it listed below.

The described solutions should apply to all versions of Thunderbird starting with Thunderbird 38, if not marked otherwise. If you are using Linux and installed Thunderbird and/or Lightning by using the package manager of your distribution, then these how-tos are not applicable - please contact the support of your Linux distribution to get help.

In general, these instructions apply to Seamonkey, however, details of the steps to resolve might be different.

Lightning disappears after a Thunderbird update (release and beta versions)

This may happen if the update of the add-on is stuck for whatever reason. Don't worry about your calendar data, it is left untouched and will be available again if you follow these steps to restore Lightning:

1. Go to the Advanced section of Thunderbird Settings and click on Config Editor...
2. Copy or start typing extensions.installedDistroAddon.{e2fda1a4-762b-4020-b5ad-a41df1933103} into the search box
3. When it is listed in the preferences list below, right-click on it and choose Reset from the context menu - the preference now isn't bold anymore and its value is empty
4. Close the editor, leave the Thunderbird options, open Thunderbird's add-ons manager and switch to the list of installed extensions
5. If Lightning is listed there, click on Uninstall to the right of the list item
6. Restart Thunderbird

After Thunderbird has been relaunched, Lightning will be back and you will have access to your calendar data again.

Lightning disappears after a Thunderbird update from 52.* to 60.* on Ubuntu (and possibly other Linux flavors)

This may happen if you originally installed the Lightning add-on via Thunderbird's add-on manager and hence from Mozilla Addons Site (AMO), as opposed to the Linux Distribution's package manager, which is a rather recent possibility. In this case, upon updating Thunderbird from version 52.* to 60.* with the package manager, only Thunderbird gets updated, as only this package is installed. The Thunderbird add-on Lightning from AMO gets disabled as it's not compatible with Thunderbird 60.*, and there is no newer add-on version available on AMO nor the new ATN site. Unfortunately, they apparently forgot to consider this case when preparing the Ubuntu package of the new Thunderbird version, and hence Lightning doesn't get installed automatically as a dependency.

How to fix:

1. In your package manager (e.g. Synaptic in Ubuntu, or apt, aptitude, ...), downgrade Thunderbird back to the latest available 52.* version via Force Version.
2. Back in Thunderbird 52.*, the calendars should be back for now.
3. Install the following additional packages via the Linux package manager, equally forcing their version on the latest corresponding 52.* Thunderbird version: xul-ext-lightning, xul-ext-calendar-timezones, xul-ext-gdata-provider
4. Restart Thunderbird, the calendars should still be there. Now, in Thunderbird's add-on manager, remove the Lightning extension (version 5.4). This removes the one version, and should provoke Thunderbird to use the installed version from the Linux sources, instead.
5. Restart Thunderbird again. Your calendars should still be there. Also, in Thunderbird's add-on manager, Lightning should still be listed, but there is no button to remove it anymore, only to disable it. It might happen that you'd have to re-activate a master password (if you had any) and re-enter all your passwords for all mail and calendar accounts as upon un-installing the Lightning extension in the previous step, for some reason Thunderbird might flush its Password Manager settings.
6. In Linux' package manager, upgrade Thunderbird and its related packages to their current 60.* version. These are same packages you installed purposefully in step 3: xul-ext-lightning, xul-ext-calendar-timezones, xul-ext-gdata-provider
7. Restart Thunderbird once again. You should be running Thunderbird in the latest version now, and with the calendars back and active.

It might even work for you, after upgrading Thunderbird to 60.* and being left without calendars, to simply install the above packages. However, in case this alone doesn't bring back your calendars, the way described above should work.

Lightning reappears after a Thunderbird update although I opted out (release and beta versions)

If Lightning shows up for you again after a Thunderbird update and you don't want to have it, uninstall it:

1. Open Thunderbird's add-ons manager and switch to the list of your installed extensions
2. Click on the Uninstall to the right of the Lightning list item
3. Restart Thunderbird

This will stop bringing back Lightning after a Thunderbird update. If you change your mind in future, simply follow the instructions to restore a missing Lightning above (while leaving out steps 4 and 5).

After a Thunderbird update, the first day of the week in the calendar views is set to Sunday

This is related to a cross update from a bundled version to a version from ATN (formerly AMO) add-ons distribution platform and cannot be avoided technically at the moment. Thunderbird 60.0 has a bug at the moment, that makes this issue appear regardless of the previous update channel. If you encounter this issue, please reset the first day in a week to your needs:

1. Open the Calendar section in Thunderbird Settings and switch to the Views tab
2. Select in the Start the week on dropdown menu whatever is right for you

Unfortunately, this might occur again if you run in the same update scenario in the future. If so, please correct the settings as described before. The Lightning and Thunderbird team tries to avoid this by distributing Lightning updates bundled with Thunderbird, for which this is not an issue.

When I use my user profile from a previous Thunderbird version with a newer version of Thunderbird, Lightning is not updated

If you are downloading a newer Thunderbird version instead of waiting for the automatic update or e.g. you want to test something it a beta version and you don't want to setup everything from scratch, you could use a previously used user profile. When doing so, the Lightning version should be updated when starting the Thunderbird with that profile. If it doesn't, then resetting will help - this doesn't affect your calendar data.

1. Start Thunderbird with the selected user profile
2. Go to the Advanced section of Thunderbird Settings and click on Config Editor...
3. Copy or start typing extensions.installedDistroAddon.{e2fda1a4-762b-4020-b5ad-a41df1933103} into the search box
4. When it is listed in the preferences list below, right-click on it and choose Reset from the context menu - the preference now isn't bold anymore and its value is empty
5. Restart Thunderbird

N.B.: if you do this e.g. for testing a beta version, and you want to continue to use that copy of the profile on a previous version of Thunderbird afterwards, you eventually would have to do the same procedure on that Thunderbird version again. Therefore for beta testing it is recommended to use a separate (copy of the) user profile.