Will not compile theme to p3t | PS3 Themes | Forum

This is my first theme, I spent ages on it so I do not want to lose it. Every time I try to compile, I get an error message. This is the error message:

C:\Users\Nathan\Documents\My Playstation Themes\Nate's Favorites\Nate's Favorite
s.p3t:
load "C:\Users\Nathan\Documents\My Playstation Themes\Nate's Favorites\preview.p
ng"
save "C:\Users\Nathan\Documents\My Playstation Themes\Nate's Favorites\preview.g
im"
load "C:\Users\Nathan\Documents\My Playstation Themes\Nate's Favorites\STK-MLB-M
IB-S2006-01.png"
save "C:\Users\Nathan\Documents\My Playstation Themes\Nate's Favorites\STK-MLB-M
IB-S2006-01.gim"
'C:\Users\Nathan\Documents\My Playstation Themes\Nate's Favorites\GREEN_BAY_PACK
ERS_nfl_football__eq_1920x1080.jpg' is not a jpeg file.

failed.

press <Enter> key...

any ideas how this could be fixed. Thanks for the help!