If the game crashes after adding custom files, developers recommend verifying game files via Steam or clearing your cache and preferences. FM 2015 Downloads - FM Scout
To use content from such a file, you generally extract the contents to your local documents folder, typically: \Documents\Sports Interactive\Football Manager 2015\editor data . Common Troubleshooting
If the editor data folder does not exist in your user documents, you must create it manually for the game to recognize the new files.