unable to start rendering

Hello, I just start using VAPOR on a win 7 64 bit laptop (high RAM and i7 CPU). I can import WRF-ARW data and tms data and visualize terrain. But when I follow the tutorial of Katrina: Make sure Mode is to set to navigation mode Select DVR panel (direct volume rendering) Check Instance:1 to enable volume rendering Every time when I try to check the Instance 1, the windows will tell me vaporgui.exe has stopped working and then vapor shuts down.I also cannot render in opened example sessions. The version 2.5.0 and 2.6.0.RC0 share the same issue. Need I install other softwares or? Thanks!