The steps below can be done if you see multiple “synchronization errors” due to adding a shared calendar to Outlook on a Windows computer.

“Synchronization errors” found in the “Sync Issues” folder:

will indicate some wording about:

“Synchronizing server changes in folder ‘Colleague Name – Calendar’
Downloading from server ‘https://outlook.office365.com/’
Error synchronizing folder
[80070005-508-80070005-560]
You do not have sufficient permission to perform this operation on this object. See the folder contact or your system administrator”

Steps to take to attempt to resolve this issue:

1) Quit Outlook.

2) Right-click the lower-left Windows Start icon, click Run.

3) In the “Open:” field of the “Run” window, type:

Outlook.exe /resetnavpane

Click OK.

4) Outlook will open. Let Outlook remain open for a while; 20, 30 seconds. Quit Outlook.

5) Right-click the lower-left Windows Start icon, click Run.

6) In the “Open:” field of the “Run” window, type:

Outlook.exe /cleanviews

Click OK.

7) Outlook will open. The synchronization errors should clear up.