Hi
Please ensure the following things are setup
1 In device manager please ensure medium changer is installed with unknown for Microsoft
http://www.symantec.com/docs/TECH33002
2 Tape drivers should be installed with latest symantec drivers if they are using h/w vendor drivers please use below link to install latest tape drivers for symantec
3 Do power cycle end of this with power off library & media server & power on library first wait for it to be intiliazed & then power on media server
http://www.symantec.com/docs/TECH165716
Thanks
