In old BOX API, I have shown the thumbnail as this method.
<img src="https://api.box.com/2.0/files/{file_ID}/thumbnail.png?access_token={token}">
However, recently, taking of the thumbnail fails.
It seems that there is no declaration of mime-type in the response header from BOX(Because some browsers shows this data as binary array). If this is not a bug, how should I display a thumbnail?