When you open Process Simulate 12.1, the coordinate system is messed up. (All wrong). Two of three axes, (example X and Y) are in line. Coordinate system axes are not (1,0,0), (0,1,0), (0,0,1), but they are more like (1,0,0), (-1,0,0), (0,0,1). Therefore, objects are not 3D, they are weird 2D.
Solution
In Tools / Options or File / Options (depending on your version). Click on Performance Tab. Then look at OpenGL acceleration level. The default is the Highest supported. Try changing to V3.0 (Frame Buffer Objects). See if there is a difference or if it fixes the problem completely. The video driver or video card may be the issue.
Notes and References
Hardware/Software Configuration
Platform: all
OS: n/a
OS Version: n/a
Product: TECNOMATIX
Application: PROCESS_SIMULAT
Version: V12.1
Function: SETUP
Ref: 002-7008001