Both the options under the first subheading in your screenie.
Actually only the main header needs to be checked, neither of those two sub-menus need to be explicitly selected.
On my system neither of them are and I have never had any .NET issues with MO.
Well, I went and checked both of those sub headings, but no change; FNIS still can't be called by MO.
EDIT: I saw Pistachoman's post. Could it be a problem with the latest version of MO? Given that fully enabling .NET 3.5 didn't do the trick and may not have been the problem...
Edited by wr1, 14 August 2015 - 11:40 PM.