A low battery, signal interference, or improper installation could be the cause of your SimpliSafe entry sensor's non-responsiveness. Make sure the sensor is within range of the base station and start by changing the battery. Additionally, use the SimpliSafe app to re-sync the sensor and look for any physical obstacles. By taking these actions, you can typically get your sensors back ... https://simplsecure.com/simplisafe-entry-sensor-not-responding/