I am running Ubuntu 22.04 and Thunderbird 115.4.1 (64-bit). I am a long time user of both Ubuntu and TB. For years, I have had calendars working with TB (& Lightning). I use a number of sources, but I am trying to slowly migrate to having one set on my phone and computer, which means using iCal. This has worked seamlessly for years, but it now isn't working on my main laptop. I have had to set up the iCal calendars twice, as one implementation allows me to setup an event, but won't show it, and the other shows the event, but won't let me set it up. Both ways are configured as R/W. That is painful, but almost tolerable, but the main issue is that the iCal calendars don't show any reminders. On the phone, they are visible, and enabled and work. Other calendars (not iCal) seem to work OK - but that isn't fully tested. I used the route to set up the calendars as described in https://frightanic.com/apple-mac/thunderbird-icloud-calendar-sync/ - and didn't use any scripts but configured them manually. There are three iCal calendars (I have no idea why, but ...) I have named the three calendars on the computer e.g. CalA1, CalA2 and CalA3 - and the "duplicate" ones CalB1, CalB2, CalB3. One thing I have puzzled over, is that the "server number" between the "CalAx" and "CalBx" are different, but constant within CalAs and CalBx. I tried setting up a new instance, but Lightning would not allow me, even though the URLs were different. However, CalAx all allow me to set events including reminders, but doesn't display them. All CalBx won't allow me to set up or edit events (providing an error on saving). In both instances, the calendars are enabled, and are set to be R/W. My ideal would be to have either CalAx or CalBx working with reminders - so it is less confusing for me! But it is the reminders that is my greatest bugbear! Any help would be most appreciated. Many thanks,