Does anyone know why I am getting this reject reason for network entry on a UE?

03/17 16:56:55.026: [mme] DEBUG: [EMM] Authentication request (../src/mme/nas-path.c:180)

03/17 16:56:55.026: [mme] DEBUG:     IMSI[311980000033212] (../src/mme/nas-path.c:181)

03/17 16:56:55.026: [mme] DEBUG: [MME] DownlinkNASTransport (../src/mme/s1ap-build.c:186)

03/17 16:56:55.026: [mme] DEBUG:     ENB_UE_S1AP_ID[41] MME_UE_S1AP_ID[17] (../src/mme/s1ap-build.c:231)

03/17 16:56:55.026: [mme] DEBUG:     IP[10.100.108.9] ENB_ID[67177119] (../src/mme/s1ap-path.c:79)

03/17 16:56:55.189: [mme] DEBUG: mme_state_operational(): MME_EVT_S1AP_MESSAGE

(../src/mme/mme-sm.c:129)

03/17 16:56:55.189: [mme] DEBUG: s1ap_state_operational(): MME_EVT_S1AP_MESSAGE

(../src/mme/s1ap-sm.c:60)

03/17 16:56:55.189: [mme] DEBUG: [MME] Uplink NAS transport (../src/mme/s1ap-handler.c:330)

03/17 16:56:55.189: [mme] DEBUG:     IP[10.100.108.9] ENB_ID[67177119] (../src/mme/s1ap-handler.c:347)

03/17 16:56:55.189: [mme] DEBUG:     ENB_UE_S1AP_ID[41] MME_UE_S1AP_ID[17] (../src/mme/s1ap-handler.c:354)

03/17 16:56:55.189: [mme] DEBUG: mme_state_operational(): MME_EVT_EMM_MESSAGE

(../src/mme/mme-sm.c:129)

03/17 16:56:55.189: [emm] DEBUG: emm_state_authentication(): MME_EVT_EMM_MESSAGE

(../src/mme/emm-sm.c:488)

03/17 16:56:55.189: [emm] DEBUG: [EMM] Authentication response (../src/mme/emm-sm.c:512)

03/17 16:56:55.189: [emm] DEBUG:     IMSI[311980000033212] (../src/mme/emm-sm.c:513)

03/17 16:56:55.189: [emm] DEBUG: emm_state_authentication(): EXIT

(../src/mme/emm-sm.c:488)

03/17 16:56:55.189: [emm] DEBUG: emm_state_security_mode(): ENTRY

(../src/mme/emm-sm.c:649)

03/17 16:56:55.189: [mme] DEBUG: [EMM] Security mode command (../src/mme/nas-path.c:207)

03/17 16:56:55.189: [mme] DEBUG:     IMSI[311980000033212] (../src/mme/nas-path.c:208)

03/17 16:56:55.190: [emm] DEBUG:     Replayed UE SEC[LEN:2 EEA:0xe0 EIA:0xe0 UEA:0x0 UIA:0x0 GEA:0x0] (../src/mme/emm-build.c:287)

03/17 16:56:55.190: [emm] DEBUG:     Selected[Integrity:0x1 Encrypt:0x0] (../src/mme/emm-build.c:289)

03/17 16:56:55.190: [mme] DEBUG: [MME] DownlinkNASTransport (../src/mme/s1ap-build.c:186)

03/17 16:56:55.190: [mme] DEBUG:     ENB_UE_S1AP_ID[41] MME_UE_S1AP_ID[17] (../src/mme/s1ap-build.c:231)

03/17 16:56:55.190: [mme] DEBUG:     IP[10.100.108.9] ENB_ID[67177119] (../src/mme/s1ap-path.c:79)

03/17 16:56:55.229: [mme] DEBUG: mme_state_operational(): MME_EVT_S1AP_MESSAGE

(../src/mme/mme-sm.c:129)

03/17 16:56:55.230: [mme] DEBUG: s1ap_state_operational(): MME_EVT_S1AP_MESSAGE

(../src/mme/s1ap-sm.c:60)

03/17 16:56:55.230: [mme] DEBUG: [MME] Uplink NAS transport (../src/mme/s1ap-handler.c:330)

03/17 16:56:55.230: [mme] DEBUG:     IP[10.100.108.9] ENB_ID[67177119] (../src/mme/s1ap-handler.c:347)

03/17 16:56:55.230: [mme] DEBUG:     ENB_UE_S1AP_ID[41] MME_UE_S1AP_ID[17] (../src/mme/s1ap-handler.c:354)

03/17 16:56:55.230: [mme] DEBUG: mme_state_operational(): MME_EVT_EMM_MESSAGE

(../src/mme/mme-sm.c:129)

03/17 16:56:55.230: [emm] DEBUG: emm_state_security_mode(): MME_EVT_EMM_MESSAGE

(../src/mme/emm-sm.c:649)

03/17 16:56:55.230: [emm] DEBUG: [EMM] Security mode complete (../src/mme/emm-sm.c:676)

03/17 16:56:55.230: [emm] DEBUG:     IMSI[311980000033212] (../src/mme/emm-sm.c:677)

03/17 16:56:55.230: [mme] DEBUG: [MME] Update-Location-Request (../src/mme/mme-fd-path.c:444)

03/17 16:56:55.231: [emm] DEBUG: emm_state_security_mode(): EXIT

(../src/mme/emm-sm.c:649)

03/17 16:56:55.231: [emm] DEBUG: emm_state_initial_context_setup(): ENTRY

(../src/mme/emm-sm.c:817)

03/17 16:56:55.234: [mme] DEBUG: [MME] Update-Location-Answer (../src/mme/mme-fd-path.c:610)

03/17 16:56:55.234: [mme] DEBUG:     Result Code: 2001 (../src/mme/mme-fd-path.c:651)

03/17 16:56:55.234: [mme] DEBUG:     From 'hss.localdomain' (../src/mme/mme-fd-path.c:680)

03/17 16:56:55.234: [mme] DEBUG:          ('localdomain') (../src/mme/mme-fd-path.c:693)

03/17 16:56:55.234: [mme] DEBUG: mme_state_operational(): MME_EVT_S6A_MESSAGE

(../src/mme/mme-sm.c:129)

03/17 16:56:55.234: [mme] DEBUG: mme_state_operational(): MME_EVT_ESM_MESSAGE

(../src/mme/mme-sm.c:129)

03/17 16:56:55.234: [mme] DEBUG: mme_bearer_find_or_add_by_message() [PTI:8, EBI:0] (../src/mme/mme-context.c:2847)

03/17 16:56:55.234: [esm] DEBUG: esm_state_initial(): ENTRY

(../src/mme/esm-sm.c:38)

03/17 16:56:55.234: [esm] DEBUG: esm_state_inactive(): ENTRY

(../src/mme/esm-sm.c:61)

03/17 16:56:55.234: [mme] INFO: Added a session. Number of sessions is now 1 (../src/mme/mme-context.c:79)

03/17 16:56:55.234: [esm] DEBUG: esm_state_inactive(): MME_EVT_ESM_MESSAGE

(../src/mme/esm-sm.c:61)

03/17 16:56:55.234: [esm] DEBUG: [ESM] PDN Connectivity request (../src/mme/esm-sm.c:82)

03/17 16:56:55.234: [esm] DEBUG:     IMSI[311980000033212] PTI[8] EBI[5] (../src/mme/esm-sm.c:84)

03/17 16:56:55.234: [esm] DEBUG:     EIT(ESM information transfer)[1] (../src/mme/esm-handler.c:59)

03/17 16:56:55.234: [esm] DEBUG: [ESM] ESM information request (../src/mme/esm-build.c:75)

03/17 16:56:55.234: [esm] DEBUG:     IMSI[311980000033212] PTI[8] EBI[5] (../src/mme/esm-build.c:77)

03/17 16:56:55.235: [mme] DEBUG: [MME] DownlinkNASTransport (../src/mme/s1ap-build.c:186)

03/17 16:56:55.235: [mme] DEBUG:     ENB_UE_S1AP_ID[41] MME_UE_S1AP_ID[17] (../src/mme/s1ap-build.c:231)

03/17 16:56:55.235: [mme] DEBUG:     IP[10.100.108.9] ENB_ID[67177119] (../src/mme/s1ap-path.c:79)

03/17 16:56:55.269: [mme] DEBUG: mme_state_operational(): MME_EVT_S1AP_MESSAGE

(../src/mme/mme-sm.c:129)

03/17 16:56:55.270: [mme] DEBUG: s1ap_state_operational(): MME_EVT_S1AP_MESSAGE

(../src/mme/s1ap-sm.c:60)

03/17 16:56:55.270: [mme] DEBUG: [MME] Uplink NAS transport (../src/mme/s1ap-handler.c:330)

03/17 16:56:55.270: [mme] DEBUG:     IP[10.100.108.9] ENB_ID[67177119] (../src/mme/s1ap-handler.c:347)

03/17 16:56:55.270: [mme] DEBUG:     ENB_UE_S1AP_ID[41] MME_UE_S1AP_ID[17] (../src/mme/s1ap-handler.c:354)

03/17 16:56:55.270: [mme] DEBUG: mme_state_operational(): MME_EVT_ESM_MESSAGE

(../src/mme/mme-sm.c:129)

03/17 16:56:55.270: [mme] DEBUG: mme_bearer_find_or_add_by_message() [PTI:8, EBI:0] (../src/mme/mme-context.c:2847)

03/17 16:56:55.270: [esm] DEBUG: esm_state_inactive(): MME_EVT_ESM_MESSAGE

(../src/mme/esm-sm.c:61)

03/17 16:56:55.270: [esm] DEBUG: [ESM] ESM information response (../src/mme/esm-sm.c:93)

03/17 16:56:55.270: [esm] DEBUG:     IMSI[311980000033212] PTI[8] EBI[5] (../src/mme/esm-sm.c:95)

03/17 16:56:55.270: [mme] DEBUG: [EMM] Attach reject (../src/mme/nas-path.c:134)

03/17 16:56:55.270: [mme] DEBUG:     IMSI[311980000033212] Cause[8] (../src/mme/nas-path.c:135)

03/17 16:56:55.270: [esm] DEBUG: [ESM] PDN connectivity reject (../src/mme/esm-build.c:39)

03/17 16:56:55.270: [esm] DEBUG:     IMSI[311980000033212] PTI[8] Cause[27] (../src/mme/esm-build.c:41)

03/17 16:56:55.271: [mme] DEBUG: [MME] DownlinkNASTransport (../src/mme/s1ap-build.c:186)

03/17 16:56:55.271: [mme] DEBUG:     ENB_UE_S1AP_ID[41] MME_UE_S1AP_ID[17] (../src/mme/s1ap-build.c:231)

03/17 16:56:55.271: [mme] DEBUG:     IP[10.100.108.9] ENB_ID[67177119] (../src/mme/s1ap-path.c:79)

03/17 16:56:55.271: [esm] DEBUG: esm_state_inactive(): EXIT

(../src/mme/esm-sm.c:61)

03/17 16:56:55.271: [esm] DEBUG: esm_state_exception(): ENTRY

(../src/mme/esm-sm.c:345)

03/17 16:56:55.271: [mme] DEBUG: [MME] UE Context release command (../src/mme/s1ap-path.c:285)

03/17 16:56:55.271: [mme] DEBUG:     ENB_UE_S1AP_ID[41] MME_UE_S1AP_ID[17] (../src/mme/s1ap-path.c:287)

03/17 16:56:55.271: [mme] DEBUG:     Group[3] Cause[0] Action[3] Delay[0] (../src/mme/s1ap-path.c:306)

03/17 16:56:55.271: [mme] DEBUG:     IP[10.100.108.9] ENB_ID[67177119] (../src/mme/s1ap-path.c:79)

03/17 16:56:55.275: [mme] DEBUG: mme_state_operational(): MME_EVT_S1AP_MESSAGE

(../src/mme/mme-sm.c:129)

03/17 16:56:55.275: [mme] DEBUG: s1ap_state_operational(): MME_EVT_S1AP_MESSAGE

(../src/mme/s1ap-sm.c:60)

03/17 16:56:55.275: [mme] DEBUG: [MME] UE Context release complete (../src/mme/s1ap-handler.c:919)

03/17 16:56:55.276: [mme] DEBUG:     IP[10.100.108.9] ENB_ID[67177119] (../src/mme/s1ap-handler.c:933)

03/17 16:56:55.276: [mme] DEBUG:     ENB_UE_S1AP_ID[41] MME_UE_S1AP_ID[17] (../src/mme/s1ap-handler.c:950)

03/17 16:56:55.276: [mme] DEBUG:     Action: UE context remove() (../src/mme/s1ap-handler.c:963)

03/17 16:56:55.276: [mme] INFO: Removed a UE. Number of UEs is now 0 (../src/mme/mme-context.c:63)

03/17 16:56:55.276: [emm] DEBUG: emm_state_initial_context_setup(): EXIT