Running Win10x64, Preview build 16273, RX-480 8GB, Crimson 17.8.2's, The program runs fantastically from the normal downloaded GOG install executable, it's gorgeous; however from Galaxy--it locks up my entire system in a crash that actually reboots the machine! A very hard crash, in other words. I redownloaded the game through Galaxy, verified the files, and then ran it from the Galaxy interface--hard crash, reboot. Reverified the files and ran it again, but this time directly from the game executable bypassing the Galaxy interface--identical hard crash, the second time.

It may be related to faulty files from Galaxy incorrectly configuring the sound support, as before the game crashes when it has been downloaded and verified through Galaxy, the sound goes crazy, echoing and stuck--repeating certain sounds until the system crashes and reboots--sounds like sound is going into an infinite loop. Uninstalling the Galaxy version through Programs and Features and then reinstalling from the non-Galaxy downloadable executable--as I say above--is the cure, as it runs perfectly from there, no trouble at all--no special config work of any kind required.

EDIT: OK, what I had to do to successfully install a running copy of realMyst Masteriece from Galaxy was to first uninstall the older version and then install the game through Galaxy to an empty directory. It would not upgrade the previous version in place, which is what I suspect caused the problems I relate above. So Galaxy works to install the DVD version, just not on top of the older CD version as an upgrade.

A peculiarity I noticed is that the file version number for the DVD version from Galaxy, reportedly the newer version as identified by Galaxy, is 4.2.2.xxxx, while the supposedly older version of the realMystMasterpiece.exe is number file version 4.5.5.xxx--the date on the 4.5.5.xxx version being a couple of *years* older than the 4.2.2.xxxx version...;)