The auto-number prefixes added in Paris for Service CIs as part of the CSDM changes cause issues with number fields due to the one field per table limitationDescriptionAuto-number fields may have been added to the CMDB over previous customizations, often at the top level of the CMDB, and covering all classes. New OOB fields and prefixes added in extending tables of the CMDB may override those existing custom fields and replace the prefix and number sequence. This may have side-effects such as breaking identification for imports that rely on the custom number field values, due to the one field per table limitation.The OOB fields [cmdb_ci_business_app.number] and [cmdb_ci_service.number] do not conflict with each other, but do conflict with any pre-existing custom number fields.The CSDM changes in Paris have added two prefixes to the number field defined on cmdb_ci_service:Prefix BSN, on Business Service [cmdb_ci_service], which affects that class, plus extending tables:SLA Configuration [em_sla_configuration]Technical Service [cmdb_ci_service_technical]Service Offering [service_offering]Service Group [cmdb_ci_service_group]Prefix SNSVC, on Monitored Service [cmdb_ci_service_auto], which affects that class, plus extending tables:Application Service [cmdb_ci_service_discovered]Technical Service [cmdb_ci_query_based_service]Manual Service [cmdb_ci_service_manual]Alert Group [cmdb_ci_alert_group]Steps to Reproduce In a pre-Paris instance, create a string field on cmdb_ci named, for example, u_ci_id.Add corresponding number maintenance records.Create a service CI. The u_ci_id field will have a prefix and number populated as per the above number maintenance records.Upgrade to Paris or later.Create a service CI. The u_ci_id field has a prefix and number with the BSN prefix and number sequence.WorkaroundThis problem has no workaround, is under review and targeted to be fixed in a future release. To receive notifications when more information becomes available, subscribe to this Known Error article by clicking the Subscribe button at the top right of this form.Related Problem: PRB1456249