ERR_CAMPAIGN_MEMBER on Salesforce: Campaign member add failed. Root cause: The Campaign Member record could not be created or updated. Salesforce enforces constraints on Campaign Member status values — they must match the picklist values defined for the campaign's member status field. Additionally, a contact or lead can only be added to a campaign once, so duplicate additions will fail. Step 1: Check membership. Verify not already member Step 2: Check campaign status. Verify campaign active Step 3: Check contact type. Verify contact/lead exists Step 4: Retry add. Attempt add again