Unable to add shared folder in OWA

[Grace Yin]

Hi,

A user has full access to another user's mailbox, also author permission to Inbox, but the user got error that "your request couldn't be completed. please try again later" when the user tried adding the shared folder in office 365 portal. 

What caused the problem? Need help!

Thanks in advance!

[#2]

Try opening the mailbox directly by clicking the user photo in the top right corner -> Open another mailbox, or typing the URL directly (https://outlook.office365.com/owa/shared@domain.com). Also, check if it works OK in Outlook, just to exclude some permissions-related issue.