Here's what you do whenever you edit the game:
1. Make a backup copy of every file in the game. What I do is open my Origin Games folder, copy the entire FIFA 13 folder, then paste it in the FIFA 13 Editing folder I created and have stored on my PC.
2. When starting a new editing project, start with something small. Edit one thing only; don't try and edit multiple files at once. If you edit too much at one time, it complicates things if you make a mistake. The fewer things you edit, the easier it is to track down what the issue is if you make a mistake.
3. When finished editing, start the game up and check to make sure your game stills runs and works properly, and that your edits worked. Go into the editing section and check the players and the team formations etc. Then start a game up to make sure that part of the game still runs properly as well. You do this every time: edit then check, edit then check again.
As for your problem, nobody here can tell you what you did wrong. You have to figure that out yourself. So delete your edited files, copy and paste your backup files into the game, and then start again and follow the steps above.