I believe this issue started with Beta 7 and it is still occurring in Beta 8. I use several functions in my title bar, i.e. Save Window Positions or Start Screen Saver.
When using either of these title bar functions after DF has been open for more than a few minutes, it crashes with this error. Screenshot attached. When using these functions right after starting DF, they seem to work fine, so whatever is causing it may not be initialized yet at that point. I can replicate this issue fairly reliably.
