so are these caldav calendars in Lightning. Or something else. I have never heard Calendars refered to a feeds before,.

Yes, Lightning, the calendar built in to Thunderbird.

Here are the URLs of two of the calendars:

http://api.meetup.com/sacgeeks/upcoming.ical webcal://www.meetup.com/sacgeeks/events/ical/

I tried the second because, as described above, no calendar items are displayed for the first. But no calendar items are displayed for the second, either.

"Calendar feed" is a term that is well used - https://www.google.com/search?q=calendar+feed - but I don't have a preference for what we call them here if that helps me get them working again.

(:

Names only matter to me in that we need to be on the same page.

But using the same URL I get a load of error in the error console of the type Timestamp: 18/08/2015 1:39:38 PM Error: TypeError: ICAL.Value.fromString is undefined Source File: resource://calendar/modules/ical.js Line: 641

I have filed bug 1195618 I would suggest you create a Bugzilla account and add yourself to the CC list. Hopefully we will see early attention to the issue, and you are really better place to answer questions than I am. I just reproduced it.

Thanks a bunch! I do have a Bugzilla account so I'll hop on over there.

Looks like you got a workaround So I am marking this post as a solution to close this topic and get it into Google.search (open topics do not get indexed) so it might appear in others searches.