have the same error message My Environment: Windows: 7 Java Version: 1.7.0_09 Yed Version: 3.10.1 Notebook with two graphic cards, NVidia and Intel graphic onboard After pressing 'OK',the error message displays immediatly again. Can't do anything with the yed window until i close yed. My Notebook is connected with an external display via hdmi. The main desktop (primary screen with the taskbar) is on the external display while the enhanced desktop (secondary screen) is on the Notebooks display. This is what I've done when the error occured: Yed was not started, so I just double clicked the .graphml file. Yed was automatically started maximized on the enhanced desktop (secondary screen)(on the Notebooks display). After closing yed and double clicking the .graphml file a second time, yed came up on the main desktop (primary screen). This time it was not maximized and no error occured. I moved the window then back to the enhanced desktop (Notebook display) and maximized it manually. Bam... the error occured again. I can maximize it on the primary screen without problems. So I switched the primary screen to the notebooks display and enhanced the desktop to the external display. As long as yed is just maximized on the primary screen everything is fine, after moving the window to the enhanced desktop and maximizing it the window freezed. No error message, the window just does'nt respond anymore.