having a problem on vanilla install, no changes accepted defaults

Have you tried changing the compatibility settings? Real Myst works for me perfectly. Try doing this:

1. Change the RealMyst Launcher (yellow icon) (in Program files Real Myst folder its "Launch RealMyst" ) compatibility settings to Windows XP SP2, and run as admin.
2. Change the game executable (.exe) which has an icon of a book in your program files and its an "Application" and change those compatibility settings to Windows XP SP2 and Run as Admin.

Game should work once you change both of those, the launcher and game executable.

Yes, I tried in 95 98 ME 2000 XP, nothing helps... I got the original myst and it works like cake

http://www.gog.com/forum/myst_series/realmyst_and_window_8_81_crash_solution

kudos to you and others it worked!

its kind of bull that GOG doesn't use that method and make the game work in 7, I mean come on 7? Even Myst and Riven Work in 7... if they wont listen to their fans its hopeless for games like these

Confirmed that it works! (Windows 7)

The solution is specifically to set realMyst's Windows Compatibility mode to Windows XP Service Pack 3. (Actually, I tried on Windows 98, and XP Service Pack 2... all worked. It looks like you just have to set *some* compatibility mode, so I'm confused about Comment 3 which says that didn't work.)

I'm confused about how this works. From what I've read elsewhere, it looks like the issue is missing Indeo codec (which is used by some -- but not all -- videos in realMyst). It seems that Microsoft removed this codec some time in 2014--2015. Maybe they make it available when using compatibility mode.

GOG should definitely update the package to set compatibility mode on by default.

This compatibility setting fixed it for me in Windows 7 as well. Also noticed a slight performance improvement in game... was running all shuddery with a GTX970 (definitely shouldn't!) but now it runs ok (still not great)