Unable to share calendar

[khan_mahindra]

Hi Folks,

A user has created an additional calendar in outlook and shared it with several people  but can not share anymore with new people , the share button is grayed out. 

Is there anyway to share the calendar. tried hard but not documented any where. 

tried OWA AND OUTLOOK BOTH AND CAN NOT SHARE IT ANYMORE

[#2]

can you share it with others via powershell (by way of a test) ?
Add-MailboxFolderPermission -Identity user:\calendar -user otheruser -AccessRights Editor