Look under Preferences > General, make sure 'Hide On My Computer folders' is unchecked.
Then go back to the Calendar view. On the left hand side now (under 3 month view) is a Calendar checkbox. Check it again and your calendar should reappear.
USB Conference Microphone for Computer, 360° Omnidirectional Condenser PC Microphones with Mute, Plug & Play Compatible with Mac OS X Windows for Video Meeting,Gaming,Chatting,Skype,VoIP Calls (Renewed) $19.90 Works and looks like new and backed by the Amazon Renewed Guarantee. In any meeting invitations that you send from Microsoft Outlook, the meeting's start time appears in the time zone that is set on your computer, not in your preferences for your WebEx service. On your WebEx site, all meeting times appear in the time zone that you set in your preferences, regardless of the time zone that is set on your computer. You can also start an instant meeting from the Mac toolbar: 1 Select the WebEx ball icon on the Mac toolbar. 2 Select Meet Now from the menu. Note: By default, instant meetings you start with Meet Now happen in your Personal Room. To change your default settings, go to your WebEx site and select. Join the video meeting first, start presenting, and then record. You can’t record if the meeting was created on a conference room device (such as Meet hardware), or was generated by another process, such as a Chrome plug in. Schedule the meeting in Calendar or be sure a person, and not a device, starts any ad-hoc meetings. MacOS 11.3 will ensure that a Mac finishes charging to 100% three hours prior to a calendar event's start time, the code suggests, although the exact timing may vary depending on whether an alert.
If this doesn't work here are some other possible things to try.
Typically issues with calendaring are caused by client issues.