Error 11 Warning when carrying out Backup

[CA1091557]

I've recently re-installed a Tape Drive (HP Surestore DAT24 Drive DDS3 Model C1537A) and I have noticed that when it is making a backup it issues a warning that the Disaster Recovery Generation has failed. Error 11 - file not found. I am using Yosemite Tapeware Version 6.20 SP3C.
Now according to my Backup literature this drive has Disaster Recovery built in and as such, I assume that it is not necessary for me to have to create Disaster Recovery Diskettes or a CD. I have also restored the database by changing the ini file settings in case that was the cause of the problem but with no success. Does anyone know why I am getting this error message. I have looked at the TwTrace.txt file (copy attached). Any help would be gratefully received.
Cheers, Greg

P.S. I cannot seem to locate any info for my Yosemite Tapeware Software on the web. Any ideas where it might have gone?