OK. Reflashed a backup. Initialised the USB (was unuverse), the system mount it as usb without asking me.
Added the line, rebooted and try to install the plugin. Now i'm at the same point before posting here.

When installing i receive this message (and this is the reason previously i mapped my usb to universe).
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Expand your universe.

Sorry no space available to expand your Universe.
To enable Parallel dimensions you need a dedicated Usb stick.

Instructions:
1) Format your Usb stick
-From Devices Manager or Telnet

2) Map the newly formatted stick to "universe"
-Go to Device Manager
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I hope now you understand why i mapped it before but now without mapping and with the line in fstab i can't install it.