Out of the blue one of my users started getting the attahched error when he tries to perform certain functions within the case entity such as attach items in the Notes entity. I double checked his permissions (via Service > Settings > Security > Users > select user > Manage Roles) and confirmed his permissions aremirroring any other user who CAN perform the same functions within the case entity. See attached screenshot and error code details.
[View:/cfs-file/__key/communityserver-discussions-components-files/763/ErrorDetails.txt]