I own a Moto X (2nd Gen) 16 Gb. The 'Total space' on the phone was 12.7 Gb from the very beginning. While download a large app (900 MB) yesterday, the download suddenly stopped with the 'Insufficient Storage Space' message, and from then on, the Total space has dropped to 10.17 GB. I have tried clearing cache, using 'Clean Master, and all else. What do I do?