Maybe try running the FeeCADLink.exe file in the bin directory as an administrator.
Got that message tooTried that, tried both downloads for windows, stable and daily. I get the same error for some missing .dll file . Oh well.
Realthunder would not install for me so I installed freecad and after it was working got Realthunder installed .
When I first installed Freecad nothing worked until eventually I changed the mouse settings at bottom right of screen.