Cubase 7.5 crash

In Cubase 7.5 and when I change drum kits in Groove Agent One or Groove Agent SE disappear the names of the drum kits in the selection window and Cubase crashes. I have to terminate the application from Windows Explorer. This problem I’ve ever had. Thank you for your attention.

My computer

PC Quad core Intel
Windows 7 64 bit
Ram 8 Gb
Pc configured for just music
Plug-in used:
EW String platinum,EZDrummer 2, Trillian, Pianoteq 64 bit, Halion SE, Groove agent one, Groove agent SE, AGG (guitar electric) , AGM (guitar acoustic).

Thank you for your cooperation.
Giuseppe Sbernini - Parma (Italy)