Hi SMButler,
I am not with Laminar Research; just a flight simmer.
My official version of X-Plane is currently mothballed on my flight sim PC. To keep abreast of what version of XP is available I downloaded the demo version onto a laptop also running Win 10 64 bit. There were no problems.
The demo version becomes the official version when the product key information is entered.
In opening the demo software and then closing I found the log.txt file in the x-plane root directory. This file is created and modified every time you run and shut down x-plane.
My suggestion would be to rerun the installer file. It will check for files with errors and overwrite those files. Use this method to update the software version. You should get a prompt to check for updates.
Good luck
Glenn