Default Unable to restore CMW backup from extsdcard

Help needed.
Made a backup in external sd (5 Gb backup)
Now I can't recovery it
This is what I am doing
- boot in custom CMW 6.0.3.3
- recovery from external Sd
- zip selected
- file not found in sdcard/clockwordmod/backup ( my backup is not there is in extsdcard)
- freeze in checking md5.

How can I solve it?