PM_CONN_SEC_ERROR_MIC_FAILURE

#define PM_CONN_SEC_ERROR_MIC_FAILURE   (PM_CONN_SEC_ERROR_BASE + 0x3D)

#include <peer_manager_types.h>

Encryption ended with disconnection because of mismatching keys or a stray packet during a procedure. See the SoftDevice GAP Message Sequence Charts on encryption (@linkBLEMSCgap), the Bluetooth Core Specification 4.2, sections 6.B.5.1.3.1 and 3.H.3.5.5 (@linkBLEcore), and BLE_HCI_CONN_TERMINATED_DUE_TO_MIC_FAILURE.