Please use the generic LTO driver built into Windows with MagStor LTO Tape Drives.
From "Device Manager" select the tape drive and right click "Update Driver".
Select "Browser my computer for driver software"
Select "Let me pick from a list of available drivers on my computer"
Select "Tape Drives" and press next
Select " LTO" and press next
You should now have successfully installed the appropriate driver for your MagStor LTO Tape Drive.
Windows Server 2012 R2 and Windows Server 2016 require a Microsoft update to utilize LTO8 drives:
Microsoft Windows Server 2012 R2 - https://support.microsoft.com/en-us/help/4041685/windows-81-update-kb4041685
Microsoft Windows Server 2016 - https://support.microsoft.com/en-us/help/4041688/windows-10-update-kb4041688