There is no importance on the disc he is making, it's the end proccess what's being impossible to complete. After you burn the CD, DVD or BRay, by default most programs leave the disc open in a registration of sessions, that way you can keep filling it until you deplete it. The problems is that until it closes the media is not readable by any other device than the writter, not only the bdplayers wont play the videos but also other computer bd-r devices will not be abble to display the content. There for, is of most importance to be abble to close the discs at any given point. The tool in the software exists, but is out dated, it does not let BluRay media to close, only DVDs and CDs. With the recent come out of discs M, DL-BluRay
and UHD in the horizon it feels like a poor service.
I purchase a licence for the last software last year, 2020. The version is 14.0.49 and very much believe that is the same that "spine" is talking about, it still stands for "Roxio Easy CD and DVD Burnirning" I can read the same thing "Disc Copy" upon the entry layout of the software sold on the 2020 version.
Last note: when marking preferences disc at once and the option close the disc explicit check. After you run the tool it still says "open, multisesion".