Symptom:
sessmgr crash Assertion failure at sess/mme/mme-app/app/mme_msg_utils.c:4954 at function mme_send_s1_ue_release

Stack (19384@0xffff9000):
    [f7e285a1/X] libc.so.6/kill() sp=0xffff9a78
    [0aa52423/X] sn_assert() sp=0xffff9aa8
    [07710aa5/X] mme_send_s1_ue_release() sp=0xffffa548
    [0773ae0e/X] mme_disp_handle_destroy_action_codes() sp=0xffffa578
    [07740c71/X] mme_disp_handle_emm_evt() sp=0xffffa658
    [07746037/X] mme_disp_ncall_answered_handle_dns_rsp() sp=0xffffa698
    [076ff6d9/X] mme_fsm_event_handler() sp=0xffffaaf8
    [07711dc2/X] mme_app_mme_dns_rsp_cb() sp=0xffffab78
    [0891d67c/X] snaptr_procedure_complete() sp=0xffffaed8
    [08919b29/X] vpnapi_query_cbk() sp=0xffffaf28
    [0ab0557d/X] sn_msg_arriving_handle() sp=0xffffd5d8
    [0aae1bc5/X] sn_loop_run() sp=0xffffdb68
    [0a8cbee4/X] main() sp=0xffffdba8

Conditions:
MME running 15.0(53496)