Hi yEd Team,
Since a couple of versions back I've found that the yEd GUI stops repainting if left open and unusued for a long time. I'm pretty sure that this is always triggered by doing a suspend/resume on my laptop, but I think I've also seen it where the GUI's simply been idle and minimised for a few hours.
I've uploaded a screenshort below. You can see that the tool bars left and right, have gone grey and then the menus don't display properly. I can still interact with the canvas, and the mouse pointer still changes context over the right-hand column and can still drag-and-drop items onto the canvas - albeit it done totaly blind to what I'm selecting. Closing yEd and reloading resolves this every time.
http://pasteboard.co/WCZcN6r.png
I'm running yEd 3.14.2 with on 64-bit linux (Mint 17.1), using the bundled version of java.
Please let me know if there's any other diagnostic data I can send to help with this.