MC4SF_MANAGE_TAGS

What this means: A Flow or invocable action that adds or removes Mailchimp tags did not complete successfully.

Common causes: Too many tag updates; missing permission set; member not found / Mailchimp API error.

What to do: Check Maintenance message. Confirm Flow user has Mailchimp permission set. Reduce tag updates per interview. Guides: Audience Tags and Invocable Actions.