The samba-tool domain backup code requires that the source domain controller already have a ridNextRid attribute, which is currently only populated for one the first user is created on that DC. The algorithm for creating the ridNextRid is known, and the dbcheck code (python/samba/dbchecker.py) already has that code. If this was shared, a 'virtual' ridNextRid could be calculated, removing this restriction.
This bug was referenced in samba master: e8c242bed19432d96e78dc345ab5f06422c5b104 658e5a6cc20b57f48477affd370fe25458178b92 b7e6a1c5da7283c49586dc29f85ab19e0e57b0f6 cc98e03e7a0f2bf7a1ace2950fe6500f53640c1b 7c7cad81844950c3efe9a540a47b9d4e1ce1b2a1 59d293b60608172ae61551c642d13d3b215924e4
This bug was referenced in samba v4-14-test: 79029224ee02ff9f240ab1a81a3372a193b0879d b226e83a3dc3c74c06e48469ec02c19cbbfb963b f9d2652a0b42c37acff3ce16f0c430f3522012e5 94ca97bd121993b461082286ae24d2510211d36e 69d8b64fdc1b2d9b5ac88385af704e2935d6ca4e a6447a1dce1bed1a33ab6aa729f5837acc3895f6
This bug was referenced in samba v4-14-stable (Release samba-4.14.6): 79029224ee02ff9f240ab1a81a3372a193b0879d b226e83a3dc3c74c06e48469ec02c19cbbfb963b f9d2652a0b42c37acff3ce16f0c430f3522012e5 94ca97bd121993b461082286ae24d2510211d36e 69d8b64fdc1b2d9b5ac88385af704e2935d6ca4e a6447a1dce1bed1a33ab6aa729f5837acc3895f6
This bug was referenced in samba v4-13-test: 445fb770c77b488c3ff7e426d985206967f5d825 00444ac64f5b9ece88a62100b9b98c6fe75f6a60 b3d59842fd99c8d72dbc6f65259efad05bd5d897 afad2fd9e2499f6ddacae9ddace22c81e9de7da0 e5c3a675464208bffad08a0e923406c9a2d4b0a5 82e0f3e79975ffdffd5afca77b6458a33488eff7
This bug was referenced in samba v4-13-stable (Release samba-4.13.10): 445fb770c77b488c3ff7e426d985206967f5d825 00444ac64f5b9ece88a62100b9b98c6fe75f6a60 b3d59842fd99c8d72dbc6f65259efad05bd5d897 afad2fd9e2499f6ddacae9ddace22c81e9de7da0 e5c3a675464208bffad08a0e923406c9a2d4b0a5 82e0f3e79975ffdffd5afca77b6458a33488eff7