Error: Journey Task Performer cant add attachment to save in DOR of the Assignee (Employee)

When a journey task is assigned to an employee and while responding he/she add attachment, Application throws error "We couldn't upload the attachment to document records. Contact your HR representative. (PER-1532709)". Tried adding 2 Function Security Policies in "Tadweer Employee" role called "Use REST Service to Add Attachment" & "Use REST Service to View Attachment" but still getting the error. In the data role and security profile, View All Documents is selected and the list is empty in the Document Types Security Profile.