If you are using EPo 5.0.0 ( Build 1160), It looks like the epo is installed more than 90 days and EPo is running with evaluation mode.
If yes, this is a known issue for EPo base version, as per the KB78686.
KB78686: ePO 5.0 servers installed with valid license key stop sending policies and tasks after 90 days
The article contains the registry fix for the EPO base version.
Try these steps to see issue resolves.