We are encountering a consistent and reproducible issue when attempting to programmatically insert and activate Smart Features in an assembly using the SOLIDWORKS 2021 COM API.

Despite following the documented workflow and official examples, IFeatureManager::InsertSmartFeature consistently returns Nothing (null) without error, and no Smart Feature is created.

We are requesting clarification on whether this represents:

• An undocumented API limitation

• A missing required workflow step

• A reference-binding constraint not exposed in documentation

• Or a known issue in SOLIDWORKS 2021

Any thoughts would be helpful.