[Samba] Failure attempting to demote a DC.

[Zombie Ryushu]

ERROR(<class 'samba.drs_utils.drsException'>): DsReplicaSync failed - 
drsException: DsReplicaSync failed (8440, 'WERR_DS_DRA_BAD_NC')
  File "/usr/lib64/python3.6/site-packages/samba/netcmd/drs.py", line 
570, in run
    drs_utils.sendDsReplicaSync(server_bind, server_bind_handle, 
source_dsa_guid, NC, req_options)
  File "/usr/lib64/python3.6/site-packages/samba/drs_utils.py", line 92, 
in sendDsReplicaSync
    raise drsException("DsReplicaSync failed %s" % estr)

This happens when I try to demote a DC Normally.