A Visual Studio specific error HRESULT for "Incompatible document data".
public const int VS_E_INCOMPATIBLEDOCDATA = -2147213334;
If the document is open in an incompatible editor CreateEditorInstance should return VS_E_INCOMPATIBLEDOCDATA or E_NOINTERFACE. If the file could not be opened for any other reason it should return an informative HRESULT error code. CreateEditorInstance may be called on various editor factories in a loop while attempting to find an appropriate editor.