User sometimes may get Auto Snapshot error e-mail. Common mistake thinking this error is directly technical, before doing that:
The instance for which automatic Snapshot is to be taken should be checked by following path: Compute > Instance
It should be checked if its on pause by using drop-box menu which located at the end of the instance line. Automatic snapshot cant be done if its on pause mode. Instance has to be open or close.
If this is not providing a solution to your automatic snapshot issue, you can always contact us via firstname.lastname@example.org