1) Please make sure to turn on the Bluetooth function if you want to connect to another device through Bluetooth.
2) If the Bluetooth enabled device uses a battery, connect your device to a power source and then try again. If the battery power level is too low, your device may be unable to pair with another device.
3) Check that your phone/tablet is compatible with the Bluetooth enabled device. If the issue only persists in one Bluetooth device, the root cause may be that Bluetooth device is incompatible with your phone/tablet.
4) If another Bluetooth enabled device is already paired, cancel the paired device and try to re-scan the connection.