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Can't Delete Events from Lightning Calendar Connected to Outlook.com via iCalendar (ICS)

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  • Last reply by john76

john76
john76
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I've successfully connected Lightning to an Outlook.com calendar using the iCalender (ICS) protocol. However, when I try to delete an event from Thunderbird/Lightning, I get this message:

Error Code: MODIFICATION_FAILED Description: If you're seeing this message after snoozing or dismissing a reminder and this is for a calendar you do not want to add or edit events for, you can mark this calendar as read-only to avoid such experience in future. To do so, get to the calendar properties by right-clicking on this calendar in the list in the calendar or task view.

And under Edit > Calendar Properties, "Read Only" becomes re-checked. If I uncheck it again and attempt to delete an event, I get the above message again (and the event does not delete).

So how can I successfully delete events in Lightning?

I've successfully connected Lightning to an Outlook.com calendar using the iCalender (ICS) protocol. However, when I try to delete an event from Thunderbird/Lightning, I get this message: Error Code: MODIFICATION_FAILED Description: If you're seeing this message after snoozing or dismissing a reminder and this is for a calendar you do not want to add or edit events for, you can mark this calendar as read-only to avoid such experience in future. To do so, get to the calendar properties by right-clicking on this calendar in the list in the calendar or task view. And under Edit > Calendar Properties, "Read Only" becomes re-checked. If I uncheck it again and attempt to delete an event, I get the above message again (and the event does not delete). So how can I successfully delete events in Lightning?
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john76 modificouno o

Chosen solution

Updating this in case anyone runs across it. You'll want to use the TBSync add on. It works really well.

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All Replies (2)

john76
john76 Question owner
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Well, here's the answer: https://thunderbirdtweaks.blogspot.com/2016/10/outlook-calendar-in-thunderbird.html

At the bottom of that article, in the comment section, someone posted this link for the latest add on file (2019) that you'll want to use: https://github.com/ExchangeCalendar/exchangecalendar/releases

john76
john76 Question owner
more options

Chosen Solution

Updating this in case anyone runs across it. You'll want to use the TBSync add on. It works really well.