The Custom Field restore fails on 2016 after upgrade from 2013

Hi,

After upgrading from 2013 we tried to rebuild the reporting database after seeing foreign key constraint errors when publishing schedules. This normally works. We removed all custom field references from OLAP cube and ran the cube successfully, backed up the custom fields and tried to restore. The error is as follows :-

• DatabaseForeignKeyViolationError:
  • DatabaseForeignKeyViolationError (50002). Details: id='50002'
    name='DatabaseForeignKeyViolationError'
    uid='146bd36f-f023-e911-b81a-005056b57059'
    .
• Error:
  • RestoreCustomFieldsFailure (25027). Details: id='25027'
    name='RestoreCustomFieldsFailure'
    uid='156bd36f-f023-e911-b81a-005056b57059'
    projectuid='092eaef7-3d43-497e-a8b6-23f43b40e3c2'
    messagetype='Microsoft.Office.Project.Server.BusinessLayer.QueueMsg.RestoreCustomFieldsTablesMessage'
    messageID='2'
    stage=''
    blocking='DontBlock'
    .
• Queue:
  • GeneralQueueJobFailed (26000) - RestoreCustomFields.RestoreCustomFieldsTablesMessage. Details: id='26000'
    name='GeneralQueueJobFailed'
    uid='166bd36f-f023-e911-b81a-005056b57059'
    JobUID='a027376b-f023-e911-b81a-005056b57059'
    ComputerName='867339e1-3e3d-400c-bad0-28f97fe6ecdb'
    GroupType='RestoreCustomFields'
    MessageType='RestoreCustomFieldsTablesMessage'
    MessageId='2'
    Stage=''
    CorrelationUID='64cfba9e-3489-10b1-6ecd-b46cd4b02b13'
    For more details, check the ULS logs on machine 867339e1-3e3d-400c-bad0-28f97fe6ecdb for entries with JobUIDa027376b-f023-e911-b81a-005056b57059.

• The ULS logs show

System.Data.SqlClient.SqlException (0x80131904): The DELETE statement conflicted with the REFERENCE constraint "FK_MSP_WORKFLOW_STAGE_CUSTOM_FIELDS_2_MSP_CUSTOM_FIELDS". The conflict occurred in database "XXXX_WSS_Content_PWA", table"pjpub.MSP_WORKFLOW_STAGE_CUSTOM_FIELDS".  The statement has been terminated. 

the problem seems to be when [MSP_RESTORE_CUSTOM_FIELDS store procedured tries to delete using statement DELETE FROM pjpub.MSP_TVF_CUSTOM_FIELDS(@siteId) and the foreign key violation takes place.

Does anyone know how to clear this?

Many thanks

Paul