Hilo is meant for personal use only and should not be shared.
The error message is displayed when you try to pair a Hilo Band to two different user accounts.
One account = Hilo Band + Hilo Cuff
Ensure that only the Hilo Band you are trying to pair is on the charger and/or the Aktiia cuff you are trying to pair is the one that is paired with your account.
Please see the following FAQ`s for further information on how to pair/unpair your Hilo devices:
How do I transfer my bracelet to a different user?
I changed my phone/I lost my phone/ My phone broke. Do I need to unpair and pair again?