[Zubersoft]

It looks like the problem is that your page order for the song is 1-50 but the file only has 48 pages in it. I'm not sure how things got in that state as MobileSheets is normally supposed to block an invalid page order. Regardless, you can fix the page order which should fix the problem, but I'm also going to add additional checks to prevent the export from failing if an invalid page number is specified in the page order.

Mike