I have it running on OS X Yosemite (10.10.4). It expects its files in the folder ~/Library/Application Support/EnergyCoin. You might need to backup old contents of this folder and then remove all files from it except wallet.dat and peers.dat, so that it will download and synchronise the blockchain anew.
OK thanks. Where do I download it from and also is there a way to download the block chain? I am a total noob with this so please speak to me as such.