MC4SF_MANAGE_MEMBERS

What this means: A Flow or invocable action that adds, updates, or removes Mailchimp audience members did not complete successfully.

Common causes: Too many members in one action; missing Mailchimp permission set; Mailchimp rejected the update (invalid email, archived member, compliance).

What to do: Check Maintenance message. Assign Mailchimp permission set to Flow/Integration User. Process fewer members per interview. Guides: Invocable Actions and User Security.