FortiView and One-Arm Sniffer

Hi, Im running a 100D (5.2.4) with a virtual firewall running as a One-Arm Sniffer.

When I browse into FortiView/All Sessions I can see there is traffic, but if I brows into FortiView/Sources(Application,Destination,Web Sites, Threats) it all empty. Logging to disk is enabled.

 What can I do to have the FortiView fully opertating so I can monitor Threats in the network?

 Slogen