lteife
There are quite a number of TechNotes and forum posts related to ' TpErrno = Robot operation failed' errors.
Very little of them were caused by faulty robot or faulty media.
https://www.veritas.com/support/en_US/article.100018475.html
Here incorrect zoning was part of the problem.
https://vox.veritas.com/t5/NetBackup/error-requesting-media-TpErrno-Robot-operation-failed-on-all-new/td-p/322652
Incorrect labels caused this problem
https://www.veritas.com/support/en_US/article.100026246
Caused by Linux device drivers
https://vox.veritas.com/t5/NetBackup/Error-bptm-pid-5832-error-requesting-media-TpErrno-Robot/td-p/583407
A post that lists various possible reasons was marked as solution, but the OP never told us what the real problem was.
Best TN ever:
Troubleshooting Robot or Drive Issues in NetBackup
https://www.veritas.com/content/support/en_US/article.100014480.html#Robot_load_issue
A number of possible reasons and troubleshooting steps are listed here.
Please add VERBOSE entry in volmgr/vm.conf on robot control host as well as all media servers, and restart ltid.
This will increase media manager logging to OS syslog (e.g. /var/adm/messages on Solaris).
Ensure that bptm log exists on all media servers with bptm logging level set to 3 (only enable level 5 if you intend logging Support call with Veritas). No restart is needed.
Check above logs after next failure.