Unable to show a simplified part in the assembly.
Solution
When a part is modified by an assembly feature, simplification is not allowed.
The reason for this behavior is due to how assembly features work...
Assembly features modify parts in the assembly but not in the actual part file.
To achieve this behavior, we actually copy the solid body of the part and
embed it into the assembly, also referred to as an override body.
Notes and References
Hardware/Software Configuration
Platform: INTEL
OS: window
OS Version: 1064
Product: SOLID_EDGE
Application: ASSEMBLY
Version: V219.0
Function: FEATURES
Ref: 001-9281897