New Lightning versions (almost) available for all Thunderbird versions

As you may have noticed, there have been some pressing issues in the last month regarding the various versions of Lightning. I’d like to give you a short summary of what happened and what the prospect is.

Lightning 1.5 (Thunderbird 13)

If you have been using a localized version of Lightning, you may have noticed that Lightning 1.5 was reset to English after upgrading. Since I was on vacation and we had some issues with the localization infrastructure, the result was that only a few locales were accepted for the release. To account for this, I have just uploaded Lightning 1.5.1 to which is back with 38 locales. It is pending review and will be available as soon as the reviewers get to it.

Lightning 1.6b1 (Thunderbird 14)

This had been delayed since I wanted to take care of the Lightning 1.5.1 release first and also due to some IT issues I will talk about later on. I have also uploaded this release to, it is available at this moment. You should get automatic upgrades if your previous version of Lightning is also a beta version. If not, head on over to the versions page to get your Lightning beta.

Lightning 1.7a2 & 1.8a1 (Thunderbird 15 & 16)

On Mac and Windows you are probably having trouble finding a compatible Lightning. There were some events that caused our nightly builds to stall.

For Mac OSX, this was a problem with the datacenter move that Mozilla Messaging did. They folded their IT infrastructure back to the core datacenter, which brought some changes also for us. The Mac builder couldn’t be migrated to the new datacenter due to power issues, so we had to order a new one. This took a bit longer than expected since I had to ask around until I found the right path to do this. The builder has arrived and is going to be set up by IT soon. In the meanwhile, the Seamonkey Project was generous enough to loan us a build machine for a short time, which I used for the previously mentioned release builds and will use for at least one set of nightly builds so we have a compatible version again. These should be available tomorrow at latest.

For Windows, there is a build system requirement that I was told requires us to upgrade to a newer version of Visual Studio. When doing so, I found out our build machine didn’t have enough space to install. Since some other things were weird with this machine too, we decided to request a new VM for Windows. This VM is now finally installed and connected. There is still one network issue to resolve and then we can use this box for our windows builds, which will return nightlies for Lightning on the Windows platform.

As always, you can find nightly versions of Lightning on the Mozilla ftp servers, for Daily and Earlybird. Check the dates of the packages before you download, if they are not recent then you need to wait another day for new builds to show up. As a small treat, the latest nightly builds support automatic updates using the addons manager. I will tell you more about this in a separate post when the builder issues have been resolved.



  1. Thank you very much for the new releases! :-)

  2. Hi, Norton is keep removing the “calbasecomps.dll”, part of Lighting addon, as being a unsafe file. Calendar is render useless after this – is a fix around this ? I am using Win 7 x64, Thunderbird 13.01 and Lighting 1.5.1. On my laptop with Vista I didn’t encounter (yet) any issue.
    Thank you,

    • Philipp Kewisch

      Yes, very unfortunate. We are in contact with Norton, but this boils down to our dll not being signed due to lack of signing certificate. We are moving towards getting rid of the dll, so I don’t think we should invest here.

  3. Thunderbird 13.0.1 and Lightning 1.5.1 on Windows 7 SP2. L1.5.1 installs but I cannot access my existing calendar information. Nothing appears in the calendar window except a few radio-buttons on the left side. Cannot create a new calendar/task etc so whole thing looks non-functioning.

    Worked fine with TB13 and L1.5. Tried multiple re-installs reboots etc.

  4. Hi there,

    thank you for your fantastic addon. I really love and enjoy it. As i have found two bugs i would like to report them. Unfortunatly the project home page ( is not accessible at the moment. And an the blog page i cannot find a link for bug reporting.
    So i try to mark report them here:

    I have a recurring event (with start and end time) in a seperate calendar. If i try to export to html or text, the calendar only includes the first of all dates.
    I have found a bug report regarding this with an answer that this is the problem of csv format. CSV means comma separated values. Of course it is possbile to export data into these format. you have to report the data seperately. If there is a problem with events without an end date you can ask the user explicitly for an end date. The same is with exporting to html. I really would like to see this feature.

    There is another bug. But maybe it depends on the other error. I tried to invite an attendee for this event. As i hit the ok button nothing happend. I was not able to attend someone.

    Regards and thank you very much.

    • now i was able to reach the project page and i see its a bug existing since 2007. I am a software developer. what if i’d like to take a look into the sources and may try to resolve that problem (with your help)? Could you please contact me under the following mail adress:



    • Like AvE/ Andre (June 18, 2012 at 10:51 am), I have not been able to invite people to new or existing events. If I invite someone and click OK, there Lightening won’t respond. I have to remove the invitee to close the window. This has been happening for quite a while, and only sometimes. Typically, I have to invite people via email, which is lame.

      • Philipp Kewisch

        Does this still happen with Lightning 1.5.2 or Lightning 1.6 ? I thought this issues was fixed between Lightning 1.5.1 and 1.5.2. Could you check your Error Console (Tools menu) if there are any errors when you try to click OK? Please email me with details or comment here.

  5. I see more and more people reporting that you can’t invite attendees to a new event.
    When you click on OK nothing happens.
    I have tested this on 2 windows PC’s (xp & win7) both with the same result.
    I did check the error console and saw this error right after I click on the invite attendees button:
    1. “Timestamp: 18/06/2012 19:13:46
    Warning: Error in parsing value for ‘min-height’. Declaration dropped.
    Source File: chrome://calendar/skin/calendar-event-dialog.css
    Line: 0” – this looks not related BUT
    2. Timestamp: 18/06/2012 19:13:46
    Error: uncaught exception: [Exception… “Node cannot be inserted at the specified point in the hierarchy” code: “3” nsresult: “0x80530003 (HierarchyRequestError)” location: “chrome://calendar/content/calendar-event-dialog-attendees.js Line: 85”]

    This is a major problem for my organization.

  6. BTW I’m using TB 13 with Lightning 1.5.1

  7. I don’t know if this is the right place to ask (probably not), but I can’t seem to find anywhere else to do so.

    I have an updated version of Lightning and I cannot delete dismissed tasks without waiting 1-2 minutes between tasks( it takes that long to delete) and multiple tasks deleted is worse if it deletes at all. It also keeps throwing an error message.

    An error occurred when writing to the calendar Home!


    This has persisted through several(3-5) updates.

    • Philipp Kewisch

      Could you give me a bit more information on this? What types of calendars do you have, just the local one from first startup? Do you get any error console messages (Tools > Error Console)? Feel free to email me

      • Hi Philipp,

        I have the same problem as “mishap” – when I try to do anything in my usual calender (e.g. create an entry, delete an entry, create a task,…) I get back following errors:

        “Warning: An error occurred when writing to the calendar: Standard_Kalender. Error Code: 0xc1f30001. Description: The calendar could not be saved; there was a failure: 0xc1f30001”

        Twenty seconds later, this comes up in the error console:

        “Error: uncaught exception: [Exception… ‘Component returned failure code: 0x804b000a (NS_ERROR_MALFORMED_URI) [nsIWebNavigation.loadURI]’ nsresult: ‘0x804b000a (NS_ERROR_MALFORMED_URI)’ location: ‘JS frame :: chrome://global/content/viewSource.js :: viewSource :: line 179’ data: no]”

        I’m using a local *.ics-calendar, which I’m connecting to via the “network-calendar”-function of lightning, namely with this path: “file:///d:/documents/Standard_Kalender.ics”.

        Rainlendar is also reading and writing to/from this calendar. Up to now there never was a problem with this configuration. Since 2-3 lightning updates I can’t really use this calendar anymore.

        Any suggestions?

        Yours sincerely,


        • Just for your information: since today I got version 14 of Thunderbird and 1.6 of Lightning but nothing has changed in respect to the issue mentioned above.

  8. Lightning with Zimbra Task Delete through iCS not been working yet … !!!

    • Philipp Kewisch

      If you are using Zimbra, I’d suggest using CalDAV anyway. Their ICS support sometimes has interoperability issues and should only be used for read-only feeds.

  9. Latest release 1.5.1 is a disappointment compared to previous release(s). I can save a new event but am not able to add contacts and send invites.

    On the invitees screen, the first entry is misaligned and, after entering attendees email addresses, you can’t accept the list and the window will only close when you cancel out of it.

    You’ve done a terrific job in helping me avoid Outlook. Keep up the (generally) good work.

  10. I am runnig Ubuntu LTS and Thunderbird 12.0.1. I downloaded the latest version of Lightning; (which sounds great by the way), and followed the installation instructions. But I get an error message saying that Lightning cannot be installed because it is not compatible with Thunderbird 12.0.1. What can I do?

    • Philipp Kewisch

      Dennis, please make sure you are using the latest version of Thunderbird, which is Thunderbird 13. If you need to use 12, then you must download an older version of Lightning (1.4)

  11. It’s actually not working on PCs either. Was yesterday, and isn’t today – totally dependent on it for work – please fix?

  12. Hello,

    in lightning it’s not possible accept invitations from Microsoft Outlook.

    Help me

    • Philipp Kewisch

      Hi Massimo, could you provide more details? Error console messages, version information? Oulook version? Which client is inviting which?

      • Hi Philipp,

        I can send you an email with a picture where you see the problem?


      • Hi Philipp,

        news ?


        • Let me add my voice to Massimo.

          I have just noticed I’ve got the same problem (TB14+LT1.6)
          The button ACCEPT …… is disappeared when receiveing invitation from MS Outlook.
          Shell I upgrade to TB 15(16?) and related Lightning ??


  13. My Lightning add-on disappeared completely from all Thunderbird menus and Tool panels so I have no way to actually enter the calendar even though I know it’s there somewhere. When I enter the Extensions menu, I can see Lightning in the list but after clicking on Options, just general Thunderbird menu pops out, not the Lightning one. I’m using Windows XP and latest editions of both Thuderbird 13.0.1 and Lightning 1.5.2.
    I’ve noticed that several other people in the different forums are experiencing the same issue.

  14. I’ve just learned about the ESR versions of Firefox and Thunderbird, and installed the actual Thunderbird ESR 10.0.6 right now. Unfortunately, Lightning (and also LightningButton) is no longer available and has been deactivated. Is there any need not to enable ESR versions to fulfill the requirements of the actual Lightning (and L’Button) version? Or is it not possible by any means?

    • Philipp Kewisch

      To use the ESR you must use an older version of Lightning, namely 1.2.x. You can get it from the “Other Versions” page on

  15. Is it by design or bug? I cannot create new task on Lightning 1.6 in Thunderbird 14.0 using network calendar. Network calendars won’t show in the Calendar dropdown box, but the choices did appeared when creating new event in Calendar.

    • Philipp Kewisch

      Some calendars might not support Tasks (i.e Google Calendar), could this be the case?

      • No, this is Kerio Connect (Exchange clone) calendar. It was working just fine with the older Lightning version.

      • Updated to Thunderbird 15 with Lightning 1.7 and still can’t create Task on network calendar – it does not show up on the drop down list. Any ideas as why?


      • Went back to Microsft Outlook. Problem solved :-)

        • Wiss, why do you name the make of Outlook when you list it and not the make of Thunderbird… this is one not-so-small reason I sometimes go to lengths to avoid products by the maker of the likes of Outlook: everyone is brainwashed and they don’t even know it !!!

  16. i am using Thunderbird 14 lightning 16. it was working fine until i have change one of the schedule task date . After that Thunderbird wouldn’t start up with lightning enable. I have reinstall lightning but still doesn’t work. At last i rename the calendar-data/local.sqlite to different name , Thunderbird start up without any problem . However , all my past schedule tasks no longer there.

    • Philipp Kewisch

      If there is nothing awefully personal in your calendar, you could send me the local.sqlite that is crashing you, maybe I can find out whats happening, and/or recover your tasks.

  17. I updated to Thunderbird 15 and now lightning does not seem to work. Please help.

    • Philipp Kewisch

      Please also update the Provider for Google Calendar to 0.16

      • Our small office is having problems with Lightning 1.7 and TB 15. We do not run Google Calendar (so the provider is not even installed), but do have shared CalDAV calendars. If the Cache is turned off (default) then no events show, if turned on then some do, but updating is not consistent (e.g. newly created events do not always show, even though they are stored).

        • Do you get error console messages when clicking on synchronize with the cache enabled? Also try enabling calendar.debug.log and calendar.debug.log.verbose, they will give you more debug messages. You can find them in options > advanced > general > config editor.

  18. I just updated to Thunderbird 14 on Linux, and then downloaded Lightning 1.6 (because teh previous one didn’t work). Now I cannot create new calendars (no possibility at all in the menu), and also cannot enable calendar caching (it’s greyed out).

    • Addition: and there is no calendar list. :(

      • Philipp Kewisch

        This makes it sound like there is some sort of incompatibility. I’d suggest reinstalling Thunderbird and Lightning.

    • Philipp Kewisch

      Could you try Thunderbird 15 and Lightning 1.7 ? Caching is disabled for those types of calendars that don’t support it (i.e a local calendar). Please make sure you are looking at the right calendar. What kind of calendar is it?

  19. Thanks for the answers, Philipp. I just updated Thunderbird and Lightning like you suggested. I only use local calendars, I didn’t know they are not cached. I wanted caching for performance improvement, Lightning 15 is still slower than the first one I had (12? 13?).

    I still cannot see calendar lists and add calendars. Reinstalling: I never did it before. When I uninstall Lightning, what will happen to the calendar data? How do I backup the calendars? Would storing “storage.sdb” somewhere on the Desktop suffice, or is it more involved?

    • Hi Liza. The local calendars don’t need to be cached, since they allow (fast) direct access. The cache is only important for remote calendars. Actually, the cache uses a local calendar internally for the backend.

      I’d suggest backuping your whole profile folder, not only the storage.sdb. This file isn’t used by Lightning anymore.

      Theoretically though you don’t need to do anything. When uninstalling Thunderbird and Lightning, the profile should stay intact. After reinstalling, you should immediately have your data back.

  20. Thanks a lot for the answer. I’ll try reinstalling.

  21. Using Lightning 1.7 and Provider for Google Calendar 0.16, I am unable to edit events that are being pulled down from my google calendar in Lightning.

    I get the error message “MODIFICATION_FAILED”.

    I am using the private ICAL URL for my google calendar and have had this working in previous iterations.

    Only change recently is that the calendar is now shared between my wife and I.

    • Do you get any error console messages? Please enable calendar.debug.log and calendar.debug.log in the advanced config editor, then you will get even more data. If you get a message with cal.safeNewXML, please doublecheck that you actually have Provider 0.16 installed.

  22. hi
    i have thunderbird 15.0 installed with add-on lightening-calender function 1.7.
    importing from outlook calender in either csv dos, csv windows, or exel format does not seem to work. no items are added to th calender at all.

    the outlook is 2003 on an xp machine , and the thunderbird-lightening is on an windows 7 machine

    • do you get error console messages? I haven’t checked our CSV import/export in a while, maybe something has broken.

  23. All of a sudden, Events and tasks are greyed out in T-bird 15/Lightning 1.7 and I cannot add either. Using a Mac with OS 10.6.8.

    Any suggestions?


    • Do you get error console messages?

      • Same Issue as Walter Wise. Using TB 15 and Lightning 1.7 on Windows trying to sync with Kerio Connect 7.4.3.
        Tasks are greyed out the message in the new task box says “Please select a Calendar that supports tasks”. Previous versions synced ok through Caldav. I recently updated to a new version of Kerio. What can I do?

        • Philipp Kewisch

          This might be an issue with Kerio. Please enable calendar.debug.log and calendar.debug.log.verbose in the advanced config editor (check Google for how), then you will get caldav debugging. There is a request with or similar, if that doesn’t say VTODO, then Kerio is not allowing tasks.

  24. Hello,

    I’m using Thunderbird 14.0 and i received the following error when i tryed to install lightning add-on:
    “Lighning coul not be installed because it is not compatible with Thunderbird 14.0”.
    What can i do to solve this thing? i really need lightning.


  25. Hi

    I have TB 15.0 with Lightning 1.7 on Linux and I am also not able to send invitations to attendees of a meeting. I can edit the meeting, add persons but when I save no mail is send out. On the error console I get the following two error messages!

    Zeitstempel: 21.09.2012 18:04:47
    Fehler: [Exception… “‘TypeError: aItem.calendar.canNotify is not a function’ when calling method: [calIOperationListener::onOperationComplete]” nsresult: “0x8057001c (NS_ERROR_XPC_JS_THREW_JS_OBJECT)” location: “JS frame :: resource://calendar/modules/calProviderUtils.jsm :: cPB_notifyOperationComplete :: line 650” data: no]
    Quelldatei: resource://calendar/modules/calProviderUtils.jsm
    Zeile: 650

    Zeitstempel: 21.09.2012 18:04:47
    Fehler: [Exception… “‘TypeError: aItem.calendar.canNotify is not a function’ when calling method: [calIOperationListener::onOperationComplete]” nsresult: “0x8057001c (NS_ERROR_XPC_JS_THREW_JS_OBJECT)” location: “JS frame :: resource://calendar/modules/calProviderUtils.jsm :: cPB_notifyOperationComplete :: line 650” data: no]

  26. I was using TB 14 and Lightning 1.6 and creating invitations with invitees added worked fine. Now after updating to TB 15 and Lightning 1.7. It doesn’t work anymore. I’ve looked at the similar comments but they don’t say what to do to fix the problem nor do they say what is being done about it. This is a fundamental feature for team collaboration. It seems to be treated a bit cavalier given the time it has been broken and the delay in the time to get it fixed. I dislike Outlook but it is starting look more appealing every day the problem remains.

    • Philipp Kewisch

      Sorry, its just hard to get extra releases out, 6 weeks is already a pretty harsh cycle for me. This is fixed in 1.8.

  27. I have just made the mistake of upgrading Thunderbird from 15 to 16 on Linux, only to find there is no compatible version of Lightening to go with it.

    This is simply not good enough, I need to have the calender, so now I have to waste half my day trying to work out how to get back to the older version which worked.

    Thunderbird without a working version of Lightening is of no use to me.

    • Philipp Kewisch

      At the time you posted, Tb16 was in beta stage, so you need to use a beta version of Lightning. Please see the all versions page for details. Now that Tb16 is released, please use Lightning 1.8.

  28. I use Tb 15 with Lightning 1.7 and Tasks can’t even be created, the buttons are greyed out.

    Is there any way to edit and handle Tasks or Notes (From Google Calendar) with Lightning. Other Programs like Rainlendar do so it, so it should be possible?

    • Philipp Kewisch

      This is usually a compatibility issue. Check your error console and make sure you are using the advertised versions.

  29. by the way.. awsome programs already!

  30. I just received the update to Tbird 16.0.1 and now my Lightning 1.8 displays all blanked out tabs and totally blank calendars. Help!

  31. Hi
    some history…….I thought Lightning was the bees knees..the best…..the only pc based calendar that could sync with google cal..then I upgraded Thunderbird to 15. Lightning stopped working and so did Thunderbird..I thought I had lost all my emails…the forums weren’t much help implying that all my email data was corrupt.. I had no backup so I was on my own. A long story but in the end, I managed to restore an older version of Thunderbird. (Lightening was uninstalled).
    much later I installed T’Bird 16.0.1 but there seems to be no compatible version of Lightning?
    If Lightning can’t reliably keep in step with T’bird I will reluctantly have to give up on it. Have you any encouraging words???

    • Lightning has one build per version of Thunderbird. Please download the corresponding version from

  32. I upgraded the Thunderbird to version 17 and the corresponding Lightening 19 that was automatically installed by the program. The result is that my calendar is no longer synchronizing with my Google calendar. I have tried to reinstall the Lightening a couple of times and have tried to link the Lightening calendar with Google calendar but it says that the Google calendar is already linked to the Lightening calendar. I am not sure what to do so as to get all my calendar entries back (the previous version (18) worked really well!
    Please advise. Thanks.

    • I’m not sure what you are referring to with 18 (do you mean Lightning 1.8 or the Provider for Google Calendar 0.18 ?), but please try updating the provider.

  33. I have Thunderbird 17, Lightning 1.9 and Provider for Google Calendar 0.18 – calendar and calendar invites work fine, except when I receive an updated/revised invite: when I accept that I get a ‘MODIFICATION_FAILED’ error. I am sure I must be doing something simple wrong. Please help!

  34. Having trouble with lightning. I cannot seem to choose a start date and end date. If I have something on the calender that spans over multiple days I have to choose each day and fill it in. For instance, I can choose 3/25 for the start day and when I attempt to change the end date to 3/27, it simply changes the entire start and end to the 27th. Searched online for a fix and cant seem to figure out the issue on my own. Any help would be appreciated.

    • Philipp Kewisch

      Try clicking the chain icon next to the dates. This links together start and end date, unchaining it will let you chose separate dates.

      The UI is not ideal, but back when it was added, none of us found a better way. It should be noted that before, the dates were always chained together.

  35. Thunderbird 17.0.2, Lightning 1.9 on Windows XP (I’m pretty sure – but is there a way to confirm the version installed & running?)

    Two questions / issues:
    1) when deleting an invitee from an established calendar event – I cannot save the new invitee list (I click OK & nothing happens, but I can exit out of the invitee list window with the x).
    Is this a known issue? Is anyone else observing the same behavior?

    2) Is there a way to force Lightning to send out calendar event email when updating an event?
    Usually, after updating an event, Lightning will not ask to send an updated email to the recipients, nor does an update get sent. I found I can force it to email by changing the start time of the meeting to another time & then back, but would like to know if there is another way to accomplish this.

    • Re (1): I think this will be fixed with 1.9.1, please see our latest blog post.

      Re (2): Updates should always be sent afaik. Do you get any error console messages in other cases?

  36. Just did an upgrade to Thunderbird 17.0.11, Lightning is not compatible. What good is this add on if it goes away when Thunderbird is updated. What if I had to rely on it?

    • Thunderbird 17 is not the latest Thunderbird version. If you upgrade to Thunderbird 24.2.0 you should be fine. If you want to continue to use Thunderbird 17, please check out the older versions of Lightning. We constantly release new versions for each Thunderbird version being released.