It appears that this has to do with plugin options. If you have enabled the internal multiplexer and want to download the 2160p version of this video, then the plugin fails to select a file to download, because there is no version of this video that is both 2160p and supported by the internal multiplexer.
I'm not sure if this is how tong2shot intended the quality selection to work, but you can fix this either by disabling the internal multiplexer or by choosing a lower quality (for example 1080p) in the plugin options.