FSXA Tweak problem

Need help recently Tweak does not work. Win 10. “build Exterior” click that and that page appears again with the dos screen behind it…. partially running but seems to be waiting. I X out of the second “build exterior” window and dos screen completes. I then go to install the mdl into a library but I get the message “this mdl cannot be used”.
set up and config seems correct. Do I need to reinstall FSDS? My machine says I have .net framework 4.7 (hopefully this supersedes 3.5 ) Thank you, Bob
Tried. Started the install - asked if I want this to take control of my machine (usual question) I click yes. It disappears and nothing happens. 4.7 I think supersedes it my machine says I already have that, even though I can't find it in control panel\ programs.

I believe I lasted used it back I March or April or so. worked then. Worried that a Win 10 update screwed it up.