Unable to export to a music file under MuseScore 2.0.3

I have recently upgraded to 2.0.3 from 2.0.2, and I have been re-exporting music files from my .mscz files. However, I have just opened one of my older .mscz files (73 kb), and I can't export it as a music file at all - the export dialog box progress bar stays fixed on 0%. I don't know if this is relevant, but as soon as I read in the file, the program jumps up to 25% of CPU and stays at that. I have always been able to export this file in the past, so what exactly has changed, and/or what am I now doing wrong? (I have tried exporting as .flac, .ogg, .wav and even .mp3.) I have attached the file, which, incidentally, still plays fine within the program itself. I have Windows 10 with 8 Gb of memory.

Thank you!