When selecting parts in Assembly, a box shows in highlight instead of the actual geometry.
Solution
Go to the Application Button at the top left of Solid Edge and select Settings -> Options. Go to the Assembly page, scroll down to the "Fast Locate Options" section and uncheck the option, "Fast locate using box display for parts".
Notes and References
Hardware/Software Configuration
Platform: INTEL
OS: windows
OS Version: 1064
Product: SOLID_EDGE
Application: ASSEMBLY
Version: V220MP8
Function: SELECTION
Ref: 001-9835702