account activities not working

==== Required information ====
- iRedMail version: 1.5.1
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Linux/BSD distribution name and version:
- Related log if you're reporting an issue:
====

please help my iredadmin account activities are not working, and in admin dashboard Top 10 Sender and recipients not working.
how can i fix this??

thank's
Best Regard