Hi Jan,
I did read forum best practices, and tried to do my best using guidelines.
Unfortunately, all that I have is DgnPlatform folder consists of docs, libs and dlls. I can share readme.htm with you, but I'm not really sure it helps. https://drive.google.com/open?id=0B6Zfx2wnTZEOREFaZGpUVVVWQkk
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I spent few more hours and found out, that in case I call LoadRootModelById() with fillCache=false and all other params as true - I got no exception.
So I read fillCache param description: "If true, calls FillSectionsInModel with DGNMODEL_SECTION_MODEL"
And it's true, I called file->FillSectionsInModel(model, DGNMODEL_SECTION_MODEL) and got the same exception.
After all the problem is API can't fill my filehandler with proper information from disk.
I manipulated with parameters for open method, but it gives no result. Still I'm not done yet :)
Best regards,
Artem