K3b will not complete a burn and verify cycle on BD-R media

                 I am having a problem burning blu-ray disks with K3b. I am trying to backup files which  add up to 21GB on to a BD-R. When it gets 99% complete I get the  following error> mkisofs 3.1a25 returned an unknown error (code 253).  I have tried updating to K3b-kf5 but it will not launch (no error  reported). All of the required support programs are up to date. Similar  problems with K3b go back several years. Nero 4 for Linux is no longer  available. I would like to find a backup program that will write across multiple M-Disks  or BD-R Disks. I am using a Pioneer BDR-2209 but K3b does the same error on my LG DE12LU30. Any help backing up my HD to BD-R disks would be  appreciated.

I don’t have a Blueray disk to test support
But years ago when I experienced similar problems with K3b, I solved by using xfburn. It’s a lot smaller and simpler and doesn’t write some unnecessary stuff to disk.