I did a search and the closest thing I could find was MC-13434, but that was months ago and was catagorized as "Resoloved".
To reproduce the bug, go onto a survival (or creative) game, take a book and quill, and press the right mouse button to open it. While the book is open, press F2 to take a screenshot.
I would expect a screenshot to be taken at that point but instead, no screenshot is taken. There is neither a confirmation message in the dialog box nor an image in the screenshot folder.