If your sensor is presenting errors, check the following:
Instructions:
Make sure you put on your sensor correctly. If you want to know the correct way to place your sensor, click here: What is the best way to place my sensor?
Make sure your sensor is charged. The RookIcon arm sensor has a rechargeable battery, if it is the RookEpic chest sensor you need a CR2032 3v clock battery. To find out how to change it, click here: How do I change the battery in my chest sensor?
Wipe the band with a moist rap to remove excess of sweat.
Check the application:
Make sure you have the most current version. If not, update your application.
If this doesn't work, uninstall the app, restart the phone, and reinstall it.
Verify that your sensor is not linked to your cell phone from the "settings" section. Device pairing must be done directly in the app.
Try pairing your sensor on another device.
Download the app on another cell phone or tablet.
Log in with your email and password.
Synchronise the sensor with the app.