Re-upload a fresh, unpacked, copy of the theme’s folder to wp-content/themes using FTP or whatever file management application your host provides.
http://wordpress.org/themes/evolve
Same for me! My theme went transparent, had to change theme.
I tried completely reinstalling the 2.9.8 theme and it did not work. WordPress says the files are incomplete. WordPress reverted my theme back to TwentyFourteen.
http://valleybaptisteureka.com/
The same thing happened to me, but then I realized I’d hardened some folders with my security plugin.
Just in case you’ve done the same thing, the fix is to remove the .htaccess file located at the /wp-content/ directory. Then it should work.
All the best,
