Open outlook
Go to file
Account settings > Account settings
Select your email address
Change
More settings
Advanced tab
Cached Exchange Mode Settings:
Enable Use Cached Exchange Mode
Apply
Next
Close
Restart outlook
Reopen outlook
Click the little down arrow at the far right of the Email Home tab ribbon
Changed ribbon to classic ribbon
Select Browse Groups in the Groups tab
Select the group you are a member of
Hit view
Open the calendar
Make sure it is added to shared calendars
Close outlook
Reopen outlook
Go to the Calendar tab
The shared group calendar is now listed as a shared calendar