Score when uploaded has an extra page! wtf!

When I open your attached file inside the application MuseScore, it also contains 5 pages.

There can be slight differences between systems or between versions of MuseScore that can make some symbols slightly wider or narrower and thus affecting the number of measures that will fit on a line. This is especially true for scores containing lyrics, since the fonts installed on one system may differ from those on another and this affects the spacing.

In order to improve the odds that your score will render the same on another system potentially running a different version of MuseScore, it is best to add explicit line breaks to make sure the other system doesn't try to fit more measures on any line, and then also reduce stretch a notch globally to make sure it doesn't try to fit fewer.

So based on the evidence here, I'm thinking it is indeed differences in the lyrics font between systems. It appears people running Windows are seeing it fit on four pages, but people running Linux (like kuwitt, and the musescore.com server) are seeing five pages. Most likely the difference is that MuseScore propvides its own version of FreeSerif that is being used on Windows, but Linux systems usually provide their own version, and I'm guessing it is ever so slightly wider, either across the board or even just in some particular characters. Or it could be the characters themselves are the same but the kerning info - what controls the space between characters - differs between the versions of the font. I can see on Windows some letters look uncomfortably close together, maybe on Linux the spacing is just a tiny bit looser.

Anyhow, again, to some extent these sorts of slight differences are going to be unavoidable, so the approach I mentioned of locking in the layout is worth following any time you want to be sure the layout you see is preserved on other systems. It's easy to do. First, Edit / Tools / Add/Remove Line Breaks, choose the "Add line breaks at end of each system" option, then do Ctrl+A and decrease stretch one notch by pressing "{". Because the line breaks are now locked, there won't be any visible change to your score, but you'll have a bit more "wiggle room" to withstand the slight differences in font width calculations from system to system.