Hi,

when I opened shared calendars from other users by clicking on "Open" -> "Other User's Folder" and left it open in the list without deleting it, I had to realize that the calendars sporadically disappeared from the list (1-2 times a year).

How can I prevent Outlook from removing shared calendars without any request?

Hi,

Since it only happens 1-2 times a year, we cannot determine the root cause of the issue. The opened shared calendars info are stored in Outlook navigation pane settings, we may try to reset the navigation pane setting to check if it may fix the issue.

To do this, exit Outlook, press Windows key + R to open the Run command, type outlook /resetnavpane and press Enter.

Note: This switch clears and regenerates the Navigation Pane for the current profile, you will lost all custom navpane settings (including opened shared calendar list) after running this command. Additionaly, since this problem happens randomly and happens after a long period, we cannot guarantee this command will fix the issue.

Regards,

Steve Fan
TechNet Community Support

The problem has been occured again. Is there another idea?