Thank for reply. In our usecase, the iOS app uses CBPeripheralManager and the remote device is the central. Can you please let me know which specific CBPeripheralManagerDelegate callback delivers CBError.peerRemovedPairingInformation to the peripheral-role app? In the CBPeripheralManagerDelegate documentation, the subscribe, unsubscribe, read, and write callbacks do not include an Error parameter. Is this error available through another callback? Can this event be delivered while the app is active, suspended/backgrounded, or terminated? If it occurs while the app is not active, will the app receive the error later when it is opened or becomes active again? If so, through which callback? Thanks!