MC4SF_PROCESS_BATCH_ITEM_SKIP

What this means: Queued updates skipped because no matching Mailchimp Member was found. Salesforce change was not sent to Mailchimp.

Common causes: Never synced to audience; member deleted/archived; Salesforce record no longer linked.

What to do: Check skipped Ids. Confirm Mailchimp Member exists. Add via Data Wizard or Manage Members, then retry. FAQ: What are Mailchimp Queue Items?.