Hi, I have W10 latest version + latest version of Thunderbird 78.5.0 (64-bits). I did not install any add-on. Just installed direct from download. E-mail accounts work fine. I have several agenda's configured (public read only and my google calendar). They display ok after enabling them. However, after a (re-_start of Thunderbird, the agenda screen items are not displayed. Empty agenda!. Pressing the [Synchronize] button does nothing. The only way to get the agenda's items back on screen is to press the 'eye' symbol next to each agenda twice (so disable and re-enable). After that agenda's appear. If I stop Thunderbird and restart, agenda is empty again. Is there some setting that is wrong? Is this a bug? Peter