Whenever I attached an image via attachment button, I can see the image thumbnail. But when I click the thumbnail for full image, it will becomes only black image.

Anyone else?

depends on what is your browser

try the same action (you've got to do repeatedly) with different browser and observe

then you will have your answer why

check on chrome mobile, and on desktop also the same.
will try clear cache and try again later..since yesterday got a forumer also mentioning the same thing.