Audit Enabled Mailboxes 0 out of 0

Audit Enabled Mailboxes 0 out of 0

Hello.
I'm Installed and configured the program.
In the Audit Configuration / Mailbox Based Auditing / Audit Enabled Mailboxes tab, Mailboxes were displayed, for example 365 of 365. "Mails deleted or moved" reports also works fine.
But, the next day, report no more been generated.
On the Audit Configuration / Mailbox Based Auditing / Audit tab, Enabled Mailboxes displays 0 out of 0.
What could be the reason of this?