Some of these issues have more obvious fixes. If you don’t have a CGM sensor running, you won’t be able to automate your insulin delivery. It may be a matter of inserting a new sensor and waiting for the warmup period. However, there may also be issues with the quality of data that prevent you from looping. For example, if your CGM shows an error message (such as "???", Lost Sensor, Weak Signal, etc.), your system cannot loop off of that information. In that scenario, you’ll have to decide to wait until data comes back, or decide to switch to a new CGM sensor. Additionally, if your controller cannot read your CGM data for any reason, you won’t be able to loop, even if the data and the sensor are “good”. This could be because your body is blocking transmission from your sensor and transmitter to the controller, or because the controller is out of range. It could also be caused by the Bluetooth being turned off on your controller. It may also be that the environment around you is very “noisy” and interfering with your Bluetooth connections between your devices.