I am having the exact same problem, and attempted the exact same steps as OP, although mine did not create the .log file in the directory I manually added.
I do not see a way to manually run Thermal Desktop directly ("run as administrator" or otherwise).
I tried opening AutoCAD in Administrator Mode first then opening the beercan.dwg through TdDwgLauncher, but I still just get the flash.
I checked firewall and antivirus and manually added exceptions for Thermal Desktop (TdDwgLauncher) with no change.
I am using AutoCAD 2025 through the 15-day trial. I am already a few days in trying to get Thermal Desktop to launch, so prompt assistance would be greatly appreciated!
You are navigating away from the AIS Discovery experience