Strange, I’m getting this response if I request v5 but without the version header it returns expected data:
{
"error": "Gone",
"status": 410,
"message": "The API version you are looking for is in another castle. See https://dev.twitch.tv/docs"
}
In general that endpoint has always been trouble due to it’s size. I would recommend sticking to https://api.twitch.tv/kraken/chat/emoticon_images as much as possible.