A new feature has been added to the game options that allows switching between OpenGL and Vulkan renderers.
This was introduced to resolve execution and graphics issues occurring in certain PC environments.
This problem is caused by certain graphics cards being incompatible with the engine.
The solution is to switch the Rendering API to either OpenGL or Vulkan, depending on compatibility.
How to change the setting:
Launch the game → go to [Option] → [Video Mode]

Find Preferred Rendering API

Choose between OpenGL ↔ Vulkan (default: OpenGL)
If you encounter a black screen or graphics errors after launch → switch to Vulkan

Restart the game after changing the setting to apply changes.
To keep your save data from the previous version:
Locate the file gzdoom-username.ini in your old version’s folder (e.g., gzdoom-redspike.ini).
⚠️ Do not copy gzdoom.ini, as it contains engine-wide settings and may cause conflicts.
Paste gzdoom-username.ini into the new version’s folder.
Launch the game – your previous save data will load automatically.