ZR = The Zero Address was lost.
Backup the datad.nv file and reorganize the books from the NewViews shell. Check the NVREORG.LOG for the journal report to select when prompted for File or Journal Report. If JR then enter JR and press enter. Answer Y to proceed without a backup as you did a backup above.
If the books cannot reorganize then you may have to upload the datad.nv file for data recovery.
Regards to All,