an error in installation and it got aborted

i am from india. i tried to install cyanogenmod cm-11-20141115-SNAPSHOT-M12-i9300.zip on my galaxy s3 but there is an error in installation and it got aborted. Error Shows: set_metadata_recursive: some changes failed E: Error in/sdcard/cm-11-20141115-SSNAPSHOT-M12-i9300.zip Installation aborted.

Please help as i forgot to make the system recovery file and backup.