When I try to launch the game, it returns the below error:

"Could not detect 640x480 High Colour graphics mode (16 bits)"

I have the game in Windows XP SP3 compatibility mode, and forced into 640x480 and 16 bit color. Does anyone know how to fix this?

Same here.
The same error. No matter what I choose for compatibility.

I have the same problem . Did you ever resolve it ?

I just had the same issue. Moving the Schizm folder to C:/Program Files (x86)/GOG Galaxy/Games/ and start the game from there did the trick. No need for compability mode or anything.

Sorry, can you explain what you did in more detail? The folder you list is the one the game downloads to by default for me, and I'm still getting this error.

Edit: Running the game through DXWnd as described here did the trick: https://www.gog.com/forum/schizm_mysterious_journey/playing_schizm_in_2022_windowed_better_fullscreening_ai_scaling

I'm still getting this error message even after trying everything mentioned here.

Edit 2/12/24: I found out that as of December 2023, ScummVM supports this game now. Runs beautifully for me.

Thank you for the edit! Your tip helped me launch the game without issues after a series of failed attempts.