For users with rooted devices, you can force legacy storage mode for FIFA 14. This is the most reliable fix but voids your warranty.
FIFA 14 on the Android platform relies heavily on external storage (SD cards) and the now-deprecated “Facebook Essentials” login framework. The “Save operation could not be completed” error typically manifests when the application attempts to write data to the local storage but is interrupted by permission denials, file corruption, or hardware disconnections. As this error renders the game unplayable or resets progress, understanding the resolution is vital for the persistent player base. save operation could not be completed fifa 14 android
Retry with exponential backoff: