How to set privilege for Activity Attachment (activitymimeattachment) in Dynamics 365 or PowerApps

One day, some of the users in my Dynamics 365 CE environment were not able to attach a document against an appointment and other activities.

A user who has a basic(user-level) create, global read, business unit edit, and global "append and append to" privileges on activities, trying to attach a document against an activity that is owned by another user/team. But unable to do it and getting an "insufficient privilege" message.

We know that there is no privilege in the security role for "Attachment" and many people suggest that attachments are handled by "Note(annotation)" privilege.

I have increased the notes privilege to global but no luck.

After doing some research, I came to know that the "Activity attachments(Activitymimeattachment)" privilege depends on Activities.

When I increased the activity  "Create, Append and append to" privilege to Global(Organization) then attachment also inherited this privilege. Hence users are able to attach a document against an activity.

Conclusion: Notes Attachment privilege inherits from Note(annotation), and Activity attachment privilege inherits from Activities.

Cheers,

Rocker