If I try to convert an email to an event on a CalDav calendar I always get the following error message: An error occurred when writing to the calendar Personal-Don't Block! Please see below for more information. MODIFICATION_FAILED 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. Then that calendar is marked with an exclamation point. I can unsubscribe and re-subscribe to the calendar and the exclamation point goes away, but I'm still unable to save the event to a subscribed calendar. I am able to convert an email to an event as long as the calendar is on my computer and not a subscribed calendar. Any thoughts?