Crying Obsidian Shaders is a shader pack, so it only works through a shader loader such as Iris or OptiFine. If neither is installed, the pack does nothing.
Load the pack
1. Launch Minecraft with your shader loader active.
2. From the main menu or pause menu, open Options → Video Settings → Shader Packs.
3. Click Open Shader Pack Folder. This opens the shaderpacks folder, not the resourcepacks folder. Shader packs placed in resourcepacks will not show up.
4. Put the Crying Obsidian Shaders file into shaderpacks. Leave it zipped unless it is already a folder.
5. Go back to the Shader Packs screen. The pack should now appear in the list.
6. Select it and click Apply or Done. The screen may freeze briefly while the shaders compile.
Check that it worked
- Load a world and look around. Lighting and shadows should look darker and moodier than vanilla.
Dark areas are where the eerie fantasy style shows most clearly.
- If everything looks like plain vanilla, return to the Shader Packs screen. Make sure the pack is highlighted and that shaders are not switched off in your loader.
To return to normal visuals later, choose OFF or (none) on the same screen.