VK_ERROR_DEVICE_LOST error in the Dolphin emulator is a critical failure indicating that the Vulkan graphics driver has crashed or the GPU has stopped responding. This error is common on devices using

(found in many Android phones and handhelds like the Retroid Pocket 4) and certain NVIDIA or AMD setups. Primary Solutions

What is the "Dolphin VK Error Device Lost" issue?

Capture logs & file a bug