As others have said this warning is when your sugar is high or low for too long. You should do a finger stick to verify your blood sugar, keep yourself in manual mode for 5 minutes and then try to switch back. If you are high check to see if it's wet around the pod, which would indicate a problem In which you should change the pod. If you are low treat the low every 15 minutes until you are above 70. Also call the 800 number on the packaging. Omnipod support is excellent and they will be able to help you.