Well, nothing really obvious in there.
Warning: -[NSWindow makeKeyWindow] called an AWTWindow_Normal 0x12075cd10 which returned NO from -[NSWindow canBecomeKeyWindow].
I would think a warning should not prevent the window from rendering its content. However, this is low-level interaction between the Java runtime environment and the operating system and out of my area of expertise, so ...
I am afraid, I do not know what the problem is or how it can be solved.