MilViz add-on payware problem -- again

Hello, 
Recently installed MilViz F-100 and had trouble due to lack of DLL.XML file.  Radarman recommended PMDG document relating to installation of missing file.  All problems resolved.  Great fix.  Many thanks.
New problem.  I've now installed MilViz F-4E and even though the computer has the previously mentioned DLL.XML file, the exact same original problem that occurred with the F-100 now occurs with the F-4.
The problem is that although the aircraft flies well and all the external parts move as expected, nothing inside the cockpit moves -- no stick or throttle movement, lights don't work, etc.
My question is will my machine take 2 DLL.XML files, or will trying to install another one mess up the F-100?  I'm running Windows 10 on an i5 at 3.3 with 12 Gb of RAM and plenty of drive space.  MilViz support pretty poor. IMHO.  Any help will be greatly appreciated.  Many thanks.