Read BOM (qty) of the assembly in non-primary Model State

[Maxim-CADman77]

I'd like to know how to read BOM (model data qty) when some custom (non-primary) assembly Model State is active. Whether it at all possible to do this without switching the model state?
PS:
I'm getting Unspecified error (Exception from HRESULT: 0x80004005 (E_FAIL)) on call for BOMViews object.

[CattabianiI]

Could you share the code that gives you the error? Just to understand better what you're trying to do.