Ignore main scene UID error in editor

Author: KoBeWi

main/main.cpp

@@ -4148,7 +4148,7 @@ int Main::start() {
 		const String main_scene = GLOBAL_GET("application/run/main_scene");
 		if (main_scene.begins_with("uid://")) {
 			ResourceUID::ID id = ResourceUID::get_singleton()->text_to_id(main_scene);
-			if (!ResourceUID::get_singleton()->has_id(id) && !FileAccess::exists(ResourceUID::get_singleton()->get_cache_file())) {
+			if (!editor && !ResourceUID::get_singleton()->has_id(id) && !FileAccess::exists(ResourceUID::get_singleton()->get_cache_file())) {
 				OS::get_singleton()->alert("Main scene's path could not be resolved from UID. Make sure the project is imported first. Aborting.");
 				ERR_FAIL_V_MSG(EXIT_FAILURE, "Main scene's path could not be resolved from UID. Make sure the project is imported first. Aborting.");
 			}