In order to get your question to the right forum, what product are you using?
I suspect it's a system setting/incompatibility [usually graphics] related issue.....could you give some info on your PC spec's?
Also, what version of Solid Edge ST6 is it? [Commercial or Student Edition]
You migh try going to [in a new "Part" file] the Solid Edge Options, and under the View tab, change the Application Display to "Backing Store".....see if this gets it going.
Design Manager Streetscape Limited
Solid Edge ST10 [MP2] Classic [x2 seats]