To easy fix all problems with running Diablo I Classic on modern systems and computers You must use cnc-ddraw (GitHub - FunkyFr3sh/cnc-ddraw: GDI, OpenGL and Direct3D 9 re-implementation of the DirectDraw API for classic games for better compatibility with Windows 2000, XP, Vista, 7, 8, 10, 11, Wine (Linux/macOS) and Virtual Machines).
Download and unpack to Diablo Folder and set the settings. It’s works with all game modes like Battle.net and Singleplayer. Also with Hellfire.
Enjoy!
Too bad Blizzard can’t lift a finger to patch this into the hosted game files.
man, you can just use win xp compatibility mode in the properties of the D1 shortcut. It works for me
Compatibility mode was something discovered/suggested back when the legacy games moved to the shop.
But, unfortunately, it doesn’t work for everyone. In addition to the sporadic reports by others, compatability mode doesn’t work for me on either of my systems. Thus many still do need the community made fixes.