An error occurred whilst attempting to update a Mailchimp record with Salesforce data. This may occur when a Salesforce user triggers an update on a contact, which in turn checks if there is a linked Mailchimp Member. It then attempts to update Mailchimp with the mapped Salesforce details. Most of the time, the trigger action is completely unrelated to Mailchimp, but if the fields are mapped, we always need to check if the data needs to be synced from Salesforce to Mailchimp (i.e. the error can typically be ignored). It's at this time an error might occur. E.g. it could be the update was triggered by a Salesforce user with limited permissions and no access to Mailchimp. See associated error for details.