I was working with release 2451 (Windows). I was working on a score. There were no problems and the program exited normally before I closed my PC down. Next day when I loaded the score it was shown in the 'thumbnail' image but the main display was blank. When I tried to move the cnetre of the display by dragging the blue box around in the thumbnail, that too went blank.
I reported a similar problem before which was a problem caused when selected jazz style chord names but I haven't used that facility since so I've no idea what I did to cause the file to be undisplayable (though it did display initially in the thumbnail, as I say). I saw today that there is a new release (2674) so I've upgraded in the hope that the file might be recovered. No luck - now both the main display and the thumbnail are blank from the start.
I really think someone should try loading this file and find out what the problem is. Then work out how it happened in the first place and check to see if the bug that caused that problem has been fixed. I'd also be grateful to receive a useable version of my score!