Hello,
I am not sure if you are aware of this, but we have been experiencing this issue for a few weeks now and I keep on forgetting to mention it.
So, when you are in the 'Media Library' and right click on an image, then go to the 'Show URL' link - that 'Copy' button does not work, and it kinda breaks the page - It won't let you click out of that box.
This does not happen every single time I do this, but enough that it has been a slight issue for us.