I'm working on an addin that creates multiple drafting views (each one containing a TextNote) before placing them on a ViewSheet through the Viewport.Create() method.
I only call Viewport.Create() under the condition that Viewport.CanAddViewToSheet(Document, ViewSheet.Id, ViewDrafting.Id) returns true for the ViewSheet and a given ViewDrafting element in my list; this method returns true for all of them.
Strangely enough, the list's first ViewDrafting element (which I should be able to add to the sheet according to the above method) creates a null Viewport when passed into the Viewport.Create() method; the remaining ViewDrafting elements create successful Viewports as expected.
I read the documentation for the Viewport class, but have yet to find anything suggesting how a Viewport could be null when the ViewDrafting element and ViewSheet element meet the criteria of the CanAddViewToSheet() method.
Is there an undocumented condition where the Viewport.Create() method returns null?