1230james wrote on Oct 16^th, 2017 at 12:29am:

I fixed it a few days ago. It seems that I went to every thread I knew except this one when I went to go post the solutions, lol Are you running FSX:SE (or FSX Boxed through Steam)? If so, try disabling the Steam Overlay on FSX.

Thanks for the fix! At least I now know why I never encountered this problem with FSX-SE - It's because I can't stand the Steam Overlay, and have had it turned off for all games, since soon after installing Steam on my PC! ;D ;D