Problem loading styles

It's always harder to diagnose a problem if you don't attach the MSCZ file in question, but the "Reset Text to Style" button in the Inspector may be needed.

Right, attaching the score is almost always important when asking for help. But note that text styles only affect the actual *style* of the text element itself - the named style that shows in the Inspector. So if you have a staff text and it uses the Staff Text style, then upon loading a new style file, the Staff Text style will be updated and your element should reflect those changes. However, if your text element does not actually *use* the staff text style because you have overriden it using Text Properties or using the text toolbar on the bottom of the screen, then you won't see the change - your manual overrides will still apply. That's why you would need to revert your manual overrides first.