From syslog, jpppd report below error message:

Apr 3 12:42:00 mx_re jpppd: %USER-3: sdb_update_client_session Line 14861 Return Code -7 Update Failed

This error message can be seen after jpppd traceoption has been enabled.

Refer below configuration:

#set protocols ppp-service traceoptions file ppp-trace

From debug info, the bbe-smgd NACK jpppd profile request and then reports this error.

Apr 3 12:42:00.905605 dyn_prof_ipc_response_msg: opcode = NAK, request_id = 0xb5f9094
Apr 3 12:42:00.905653 NACK received for profile request with id=0xb5f9094 from bbe-smgd daemon: Failed to get SDB snapshot retry FALSE result 0x00000005
Apr 3 12:42:00.905732 sdbId 6|dynProfileResponseHandler: Profile NAK for sdbId 6 serviceTypes 0x1, action code 2, result code 5
Apr 3 12:42:00.905752 sdbId 6|dynProfileResponseHandler: error daemon (bbe-smgd),: error message (Failed to get SDB snapshot),: retry (FALSE),
Apr 3 12:42:00.905778 sdbId 6|SEQ: sdbId 6, profile deactivate response(NAK), services(dyn ), func profileDeactivateResponse
Apr 3 12:42:00.905795 sdbId 6|dynamicProfileDeactivateResponse: serviceTypes 1, response 2
Apr 3 12:42:00.905821 sdbId 6|LinkSubscriberMgr::profileDeactivateResponse: sdbId 6, serviceTypes 1, response 2, appliedConfigBits 0x00000000 0x00000001
Apr 3 12:42:00.905832 sdbId 6|LinkSubscriberMgr::profileDeactivateResponse: sdbId 6, CommonLinkSubscriberMgr not found, generic processing
Apr 3 12:42:00.905845 sdbId 6|LinkSubscriberMgr::profileDeactivateResponse: sdbId 6, appliedServiceTypes 0x0, pendingCount: 0
Apr 3 12:42:00.905856 sdbId 6|LinkSubscriberMgr::profileDeactivated: sdbId 6
Apr 3 12:42:00.905867 sdbId 6|LinkSubscriberMgr::initiateSubscriberTermination: sdbId 6
Apr 3 12:42:00.905880 sdbId 6|LinkSubscriberMgr::displaySequencerFlags: sdbId 6, SequencerState: idle
Apr 3 12:42:00.905899 sdbId 6|... : RD2A:0 APND:0 LGIN:0 PREQ:1 PRFI:0 CFGD:0 PACK:1
Apr 3 12:42:00.905919 sdbId 6|... : LOPN:0 LOUT:1 TTED:0 TING:1 LL2D:1 TREQ:0 TPND:0 PDRQ:0 PDIP:0
Apr 3 12:42:00.905939 sdbId 6|sessionDbSetStateTerminated: entered
Apr 3 12:42:00.906000 cache get 6, not found
Apr 3 12:42:00.906065 sdbId 6|sessionDbSetStateTerminated: Session removePrivateData failed for IFL name <UNKNOWN>, IFL index 0, sdbId 6, returned error <Error:libjuniper++ class=2, code=7> (SDB data not found)
Apr 3 12:42:00.906114 cache get 6, not found
Apr 3 12:42:00.906164 sdb_update_client_session Line 14861 Return Code -7 Update Failed
Apr 3 12:42:00.906255 sdbId 6|sessionDbSetStateTerminated: Session update failed for IFL name <UNKNOWN>, IFL index 0, sdbId 6, returned error <Error:libjuniper++ class=2, code=7> (SDB data not found)

The NACK reason is pppop dynamic profile only configured one authentication mode(chap or pap).

But pppoe subscriber requested ppp authentication with the other one.

For example, pppoe dynamic profile configured ppp-options to chap.

#set dynamic-profiles pppoe-profile interfaces pp0 unit "$junos-interface-unit" ppp-options chap

Subscriber requested with pap authentication mode only.

12:56:57.718247 In
    Juniper PCAP Flags [Ext, In], PCAP Extension(s) total length 22
     Device Media Type Extension TLV #3, length 1, value: Flexible-Ethernet-Services (52)
     Logical Interface Encapsulation Extension TLV #6, length 1, value: Ethernet (14)
     Device Interface Index Extension TLV #1, length 2, value: 169
     Logical Interface Index Extension TLV #4, length 4, value: 360
     Logical Unit Number Extension TLV #5, length 4, value: 32767
    -----original packet-----
    00:10:94:00:00:05 > 2c:6b:f5:5b:1b:52, ethertype 802.1Q (0x8100), length 38: vlan 100, p 7, ethertype 802.1Q, vlan 100, p 7, ethertype PPPoE S, PPPoE [ses 1]LCP (0xc021), length 10: LCP, Conf-Nack (0x03), id 174, length 10
    encoded length 8 (=Option(s) length 4)
    0x0000: c021 03ae 0008
     Auth-Prot Option (0x03), length 4: PAP  <<<< PAP only
      0x0000: c023

If customer confirms that ppp-options configuration is correct, this error message can be ignored safely.

Once disable jpppd traceoption, this error message will be disappeared.