Lighing and Daily Trunk, Windows XP SP3. The numbers below indicate the day in October 2012. Daily 08 + Lightning 08: calendar pane empty Daily 08 + Lightning 07: calendar pane empty Daily 07 + Lightning 07: calendar pane working Paenglab is able to reproduce the issue and will check if it also happens on Linux. A local build later today worked normal, so maybe this bug can be closed tomorrow (even if it is still unclear what broke). The error console shows on calendar errors: Error: TypeError: Components.classes[cid] is undefined Source file: resource://calendar/modules/calUtils.jsm -> file:///F:/Mozilla/Debugging/Thunderbird/Profiles/unstable/central/Test-central-EN/extensions/%7Be2fda1a4-762b-4020-b5ad-a41df1933103%7D/calendar-js/calUtils.js Line: 14 Error: NS_ERROR_XPC_GS_RETURNED_FAILURE: Component returned failure code: 0x80570016 (NS_ERROR_XPC_GS_RETURNED_FAILURE) [nsIJSCID.getService] Source file: chrome://calendar/content/calUtils.js Line: 96

Sorry for the confusion, Lightning 08 is in reality Lightning 07, hadn't checked the date in the latest-comm-central folder.

Todays Linux Daily doesn't start with Lightning (latest from 25.9.) enabled. On Win7 I tried the XPI from my build on Daily and this works. I think when new Lightning are built all works again.

Archaeopteryx, this may be the calDateTime.cpp implementation not loading due to the regression you filed another bug about. It may also be that there are no new nightly builds for after the merge available. Could you check both things?

Yes, this could be related to the ftp server not offering new Nightly Lightning builds (last one is 2012107). I built Thunderbird and Lightning yesterday evening on Try and these worked.

Due to the lack of recent Lightning nightly builds I tested my own Lightning builds with todays Thunderbird nightly builds. Works for me: Lightning 2.1a1 (20121009) with Mozilla/5.0 (Windows NT 6.1; WOW64; rv:19.0) Gecko/19.0 Thunderbird/19.0a1 (BuildID 20121009030549) Works for me: Lightning 2.0a2 (20121009) with Mozilla/5.0 (Windows NT 6.1; WOW64; rv:18.0) Gecko/18.0 Thunderbird/18.0a2 (BuildID 20121009053408)

New linux x86 and windows nightly builds are available: https://ftp.mozilla.org/pub/mozilla.org/calendar/lightning/nightly/latest-comm-central/

Everything works as expected with Daily 20121012 and Lightning Trunk nightly 20121011 (12 wasn't out yet).