App crashes when opening document

[djFlippy]

While working on a design on an art board, I encountered a white screen that would not go away and ultimately crashed the app.  I was drawing the box on the screen to show the text and my pencil went outside the board area; that’s when the white screen occurred.  Now the thumbnail is just zoomed in checkerboard canvas.  When I attempt mp to open the app, it immediately crashes no errors no messages.