Failed to backup to Tape Drive

Hi,

I have just updated my Acronis Backup 11.5 to the latest build version and noticed my backup to Tape Drive (Autoloader) has not been once successful. A summary on the backup policy here. First backup will go to NAS and once completed, it will replicate it to the Tape Drive. So far, backup to NAS has no problem at all and the issue is only when it's going to replicate the backup to Tape Drive after that.
For the past 2 weeks, I've been checking with Acronis Support for solution and below is some of the steps that were suggested and done by myself:
-Rebooted the backup server.
-Updated Tape Drive's driver (HP) to the latest version.
-Deleted the Acronis Provider from the Registry.
-And some other small steps.

Below is the error log, and i wonder if any one did face this issue before?

Failed to execute the command.
Additional info:
--------------------
Error code: 41
Module: 307
LineInfo: e6792a5ee190dda6
Fields: $module : agent_protection_addon_vs_38573
Message: Failed to execute the command.
--------------------
Error code: 4
Module: 7
LineInfo: 9d2de1f088cbc58b
Fields: $module : storage_server_archive_manager_vsa64_38573
Message: Write error.
--------------------
Error code: 17
Module: 336
LineInfo: e2f3e31de6157142
Fields: $module : arsm_service_vs_38573
Message: Failed to lock a drive of the library.
--------------------
Error code: 108
Module: 336
LineInfo: de5bb44dcfb05649
Fields: id : 19CB6C8B-7014-4D5B-9E11-763376A5C4CF, displayName : HP 1x8 G2 AUTOLDR 4.10 (MXA318Z05D), $module : arsm_service_vs_38573
Message: No drives are available.
--------------------

Thanks,
Jack