So if you get and error saying something about your header.php, edit the header file, and find this:
CODE
include("themes/$ThemeSel/theme.php");
Go into FTP and find the php-nuke themes folder, and find a theme you want to use. Make sure you use the exact same name in the FTP. So let's say theres a theme called "default". Edit your header file and find the code I put above. Then edit it so it looks like this:
CODE
include("themes/default$ThemeSel/theme.php");
replace default with whatever theme is in your folder, it can be any theme. Yes, leave the $ThemeSel after the theme name.
If that doesnt work, I thinkt theres another spot in the header file that looks similar, just put the default thing in there again. Re-upload the header file, and you should be good to go!

