Hello there David gosley. We have read your message. We try to help you. A reminder from your calendar? Oké one of your windows isn’t t working while you put your cursor on the dismiss button. The x button. Is that issue still there? A reminder on the calendar with what calendar do you work? For the issue solver it is that your lightning calander. Must be up to date ,is your software for lighting up to date? So make shore that you use the latest version of calendar of this type. https://addons.thunderbird.net/en-US/thunderbird/addon/provider-for-google-calendar/ The other option is that your settings for the calendar are not to read only. How to check that right click the calendar go to properties to check. Did these option work for your issue or did the functions go automatically back? If your using a url to get to your calendar try to use the extension / addon. There you use your id only. Greetings Firefox volunteer.