In Revit 2017, importing an .adsk model made in Inventor yields varied results.
Sometimes the model will not show in a section view and other times it will.
Sometimes it will cut in a section going one way (ie: viewing north) but not the other (viewing west)
Sometimes it will cut just fine.
They will always show if they are not being cut through at all.
The instances are completely random.
Issues were usually solved by changing the model to an assembly before converting in Inventor, other times by simplifying it into a part.
Other solutions were to save the .adsk model to another folder.
Some could never be solved.
Making these two programs work together better would benefit everyone.