Can someone tell me why this sprite wont work?

I am almost 100% sure everything is correct for it, but it just will not work in the engine, have had trouble with it before, but I am sure I got everything right? Thanks for helping :)

That's because MV thinks that's not one sprite, but a sheet of 8 sprites by default. What you need to do is add a dollar sign before the filename, so in your case $npc fall.png
You can read up more on this here.

Thank you, all the stuff we have had to go through to get this to work, it slipped my mind :)

I'd also remove the space, as that can cause problems when you deploy. Remove spaces from ALL your resource names :)