Hi there. Thank you for reaching out and we're sorry for the trouble. Can you please send us the screenshot of the error message showing on the app? Can you please try to sync all the flight records on your DJI Go 4 app then reinstall the app to check if the issue persists? You may also update/refresh the firmware of the aircraft using the DJI Assistant 2 software which can be downloaded on the link below. Please keep us posted. Thank you.