Your linked topic has so many issues it is not funny. Your request for support also has issues, primarily you do not appear to be aware Lightning has been gone from Thunderbird for years and that caldav is a protocol like carddav, IMAP or POP. Apparently you have found something that refers to the use of caldav, I do not have the benefit of knowing what that is, so have no idea where it goes off the rails, or even if it does. As David explained in that topic you linked to, you don't get to pick the caldav protocol, you get to input the URL to the caldav server that will offer the calendar.

This is slightly different for some calendar providers like Google where Thunderbird actually knows the link, so it finds your calendars for you.

At the end of the day, what caldav provider are you trying to use? If it is the apple product you are in for a world of pain, because Apple hides the endpoint and you have to read arcane apple setting files to find it. If it is google, you simply enter your gmail user name and password when prompted. Other providers requirement vary, so knowing which is being invoked makes the whole support thing immeasurably easier.

Hi Matt

Thanks for the reply. Indeed I am not aware Lightning has gone from Thunderbird because I am still using it! I imagine what you are saying is that it has been absorbed into Thunderbird.

I am just trying to link up the calendar of two local boxes on the same local network. They are mirrored using syncthing. At one point in the history it was possible to just mirror the directories, but that stopped working.

I get caldav from every posse of hits when I google sync Thunderbird calendars.

If you could let me know the simplest possible way of linking my two installs I would be very grateful. I am running LInux Mint MATE 21.01.

You need a caldav server to do the syncing. Apparently you do not have one, so clearly it is not going to work using caldav. A future release (in the next year) will have some version of Firefox sync. If it will do calendars or do them well I have no idea. It is currently enabled in the pre-release versions, but I have not tried it. https://download.mozilla.org/?product=thunderbird-nightly-latest-SSL&os=win64&lang=en-US

Thanks again. At least I have established there is no easy answer I am missing out on!

Will try out this new nightly for Thunderbird. But the way you phrased your message got me thinking. A quick google and I realise I can set up caldav in Cpanel in my hosting. The instructions look fairly simple so I will try that next.

Thanks for all the help. (I'm clicking on the thumbs up for your last message but it is not reacting.)

caldav is relatively simple using cpanel is my understanding. Just be aware prerelease versions are hard to get off of with your existing profile intact, so try it with a new profile that you can delete is it turns out buggy.

Thanks again Matt. Will wade in when feeling strong! And report back. :)