Meeting request in Thunderbird

This is a known problem with the Thunderbird/Lightning combination. There is a small workaround though found here:

You need to set "display attachments inline", then you can accept or decline invites though a button at the top of the email-preview. You can also drag the ics-attachment to the calendar-button in the mode-toolbar. Lightning doesn't register itself as the default program for .ics files (yet).

It would be helpful if you could add a bit more information - what version of Thunderbird are you using? What version of Lightning are you using? What was the update (or updates) that caused the problem? What addon(s) are you using apart from Lightning?

Using Thunderbird 2.0 and Lightning 0.9 this works for me. You could backup your profile, uninstall the Lightning addon, uninstall Thunderbird, then reinstall Thunderbird 2.0 and the Lightning 0.9 addon.

Could it be that something has changed on your manager's side? I believe this option needs to be selected in Outlook 2003:

Tools > Options > Calendar Options... > When sending meeting requests over the Internet, use iCalendar format

I am using Thunderbird 3.0.10, and Lightning 1.0b2pre. When I receive an Outlook email invite I see a meeting.ics attachment, which can be viewed (and that's all) by checking View->Display Attachments inline.

In order to get these into my Lightning calendar, I have to save the attachment, then use Events and Tasks->Import and choose the saved meeting.ics. This works! I can then open the event, update it, and once it's in the calendar I even see the buttons accept, etc.

Whew!