We apologize for any inconvenience. Since image enlargement at waifu2x is heavily loaded on the server, if usage is concentrated, there are cases where conversion fails.
Sorry to interrupt you, but please use the waifu2x-multi Pro. It is paid service that you can use comfortably without waiting and use it at any time. Since we need a high-performance server to operate waifu2x-multi, sales of paid service waifu2x-multi Pro will be used as server operating expenses.