Error 0x8065000C

Value: -2140864500 | 0x8065000C | 2154102796

What does it mean ?

E_BLUETOOTH_ATT_INSUFFICIENT_ENCRYPTION_KEY_SIZE  
The Encryption Key Size used for encrypting this link is insufficient.
Value: 12 | 0x000C | 0b0000000000001100

Where does it come from ?

FACILITY_BLUETOOTH_ATT  
Bluetooth ATT (Attribute Protocol)
Value: 101 | 0x065 | 0b01100101

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