If there are no power or cadence readings being displayed for a bike during your class, you need to figure out where the connection loss is occurring. Follow these basic troubleshooting steps to see if you can narrow down the cause.

Has there recently been a power meter replacement on a bike?

Occasionally the Stages Cycling bikes require replacement power meters. When this occurs, the ANT+ ID needs to be updated within Stages Flight as well. The ANT+ ID is how Stages Flight is associated to a certain bike. 

Does the power meter pair to the console?

Turn on the console by pressing the stage button and pedal/ride the bike. If the console is displaying power, then the power meter is paired to the console correctly, and this indicates the issue lies in the pairing set up with Flight. If the power meter is not displaying power, see also: How to pair a power meter with the SIC1 console, How to pair the Stages power meter with the SIC2 console, Changing the batteries in the Stages Power meter (971-0100 & 971-0101), and Changing the batteries in the Gen. 3 Stages indoor power meter (971-0103)

Is the power meter correctly paired in flight? 

Alternatively, is there a digit missing in one of the ANT+ ID numbers? The ID should be 5 digits, including a zero before any 4-digit ANT+ ID. Ask your club admin to edit the ANT+ ID number within Flight.

Please click on this link for additional questions and information regarding the Stages Power Meter.