With a recent update to Thunderbird I get repeated reminders for events (in a Gmail/Google calendar) that can't be dismissed. The error states: "An error occurred when writing to the calendar d.......@gmail.com! Please see below for more information." Details read as follows: "MODIFICATION_FAILED Status Code: 2,147,500,037, null Server Replied with 400 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." They're thrown the next time I start Thunderbird, as well. What gives? Please don't ask if I have permissions to my own Google calendar. I do. If I log into the same account on the Web, I can edit calendar events to my heart's content. I can change them, create them, delete them, etc. all I want. I am also not going to set this calendar as read-only, as the Thunderbird error message instructs. That is not an option; it won't happen; and it's not even a solution. Any other ideas are welcome. Thanks!