OPManager's schedule report suddenly stopped mail report to me.

OPManager's schedule report suddenly stopped mail report to me.

Two years ago I have set the OPManager to mail a schedule report every morning at 7:00.
And I have been receiving a mail every day till a month ago. And then suddenly the report mail stopped.
I noticed this last week and checked the settings but nothing has been changed.
Cold someone tell me
1.Is this happen occasionaly on OPManager?
2.How can I prevent from stopping the report?

                New to ADSelfService Plus?