L&TT Device Not Accessible - LTO-3 Ultrium 920 on Win2012 R2 Essentials ROK

[francobustaffa]

I have a Proliant ML310eG8 using an internal H222 Host Bus Adapter. The LTO-3 Ultrium 920 is connected to the H222.
The operating system has just been installed. I have updated firmware and drivers with Proliant Service Pack 04/2015.

Windows is updated.

I have a very strange error.

when I install the LTT utility all is OK, I can see the SCSI tape and perform the tests successfully. If I close the utility and launch again does not work reporting

'Device class name '\\.\PhysicalDrive0\' file open failure

'Device class name '\\.\Tape0' file open failure

 and others error.

If I uninstall LTT and reinstall it, the utility works the first time in the right way but if I close it and restart it does not work with always the same error.

I stopped the backup sofware in all tests. The backup Yosemite 10.4 seems to work  and  it closes the bacup without errors.

Help me!

Thank you in advance!

Ciao!

Franco