|oldPath||The path where the asset currently resides.|
|newPath||The path which the asset should be moved to.|
string An empty string if the asset can be moved, otherwise an error message.
Checks if an asset file can be moved from one folder to another. (Without actually moving the file).
All paths are relative to the project folder, for example: "Assets/MyTextures/hello.png".
See Also: AssetDatabase.MoveAsset.