This is a quote from a similar thread:
Your computer were shutdown unexpectedly while your game was running, so a file got corrupted.
Press windows button, then click on my computer button, right click on your C hard drive, then click on Properties, click on tools tab and in error Error-checking, click Check Now.
You could also try to delete the file but this can fail if there are errors on the hard disk. Deleting this file will not affect your game.
You could also go to start and type in "chkdsk" to run the utility. Hopefully that will work!
If you download this (http://www.mediafire.com/download/2h3551xrc43cb5o/media.zip) it will give you a new media folder. Open up the folder and drag the 'overlays' and 'terrain' folders to your FeralHeart folder. I would make a back up of any maps you have made in your terrains folder so you can add them back after replacing the folders. Also, with the Chkdsk Utility, try this. (http://answers.microsoft.com/en-us/windows/forum/windows_xp-system/how-to-run-chkdsk-utility/497af3dd-82cf-416b-b67c-698450ceacfa)
I hope this fixes the problem.