SQL Server backup Error - status 96

Have you been able to do ANY backups in this environment?

Seems you have been battling since August:

 EMM status: No media is available

 Managing barcodes 

Have another look at my last post on 19 Aug in your other forum discussion :

hcart drive type needs hcart (NOT DLT) media and hcart STU.
hcart2 drive type needs hcart2 (NOT DLT) media and hcart2 STU. 

qscsi - 1/4 Inch drive type needs qscsi - 1/4 Inch  (NOT DLT) media and qscsi - 1/4 Inch  STU.

So, you have DLT media and qscsi - 1/4 Inch Storage Unit.
The densities do not match.
That is why you are getting status 96 error.

PLEASE get barcode labels for the media and ensure that densities match:
drive type, media type, STU type.

You also seem to have added LTO4 labels on the tapes (L4 suffix). 
What type of media is actually in the robot?

LTO6 drive can read LTO4, LTO5 and LTO6 media, but can only write LTO5 and LTO6 media.

So, not a good idea to have LTO4 labels on the tapes. 

PLEASE go through advice in this and your previous 2 posts again and start over....

If you have LTO6 drives and LTO6 media, your drives, media and Storage Unit should all be hcart3.