Fix #15985

src/video/android/SDL_androidvulkan.c

@@ -144,6 +144,11 @@ bool Android_Vulkan_CreateSurface(SDL_VideoDevice *_this,
                             " extension is not enabled in the Vulkan instance.");
     }
 
+    if (!windowData->native_window) {
+        // passing a NULL window violates Vulkan spec
+        return SDL_SetError("Android native window is not available for surface creation, usually because of backgrounding");
+    }
+
     SDL_zero(createInfo);
     createInfo.sType = VK_STRUCTURE_TYPE_ANDROID_SURFACE_CREATE_INFO_KHR;
     createInfo.pNext = NULL;