When you route a document set to a site where no document set rules exist, an unexpected error is generated.
Consider the following scenario:
You enable the SharePoint Document ID service.
The expected Document ID column is created in some document libraries, and the Document ID column is populated.
In this scenario, the Document ID column isn't created for other document libraries as expected. Additionally, although you don't receive error messages about this issue in the user interface, you find errors in the SharePoint Unified Logging Service (ULS) logs that resemble one or more of the following:
w3wp.exe (<PID>) <thread> Document Management Server
Records Center 319f Unexpected
OfficialFile: File https://contoso/sites/<site collection>/sites/<source site>/<filename> was not saved at router location /sites/<destination>/DropOffLibrary. Exception Object reference not set to an instance of an object. thrown at: at Microsoft.Office.RecordsManagement.RecordsRepository.OfficialFileCore.SaveFileToFinalLocation(SPWeb web, EcmDocumentRouter router, EcmDocumentRouterResultProperties resultProps, Stream rgbFile, Hashtable fileMetaData, String strSourceUrl, String strUserName, Boolean bCopy, Boolean bIsDocSet, Boolean bIsDropOffZone, SPListItem& itemFinal)
Routing Engine: No rules were configured for site
Routing Engine: None of the rules in the set succeeded
This issue occurs because the destination site is missing Document Set rules.
To fix this issue, create Document Set rules at the destination site that's indicated in the ULS log error message.