The error is happening because this patient has a subscriber listed other than "Self". The system is requiring you to edit and update the "Insured Person's" information under the Insurance tab. Once you Click on the Insurance tab, go to the Insured Person, edit and save the demo information, then click the Update Exsisting Insurance button.
Then you can edit the Patient Info tab and Save your changes. This is a system requirement and will happen if not done by editing the insured person first and then the patient info.