If you get the message “The SCAP database is required” the scap data from the feed hasn’t been loaded yet. Especially if “Feed Status” page shows “Update in progress”. You need to be patient until the gvmd log says “update_scap_end: Updating SCAP info succeeded”. Please take a look at Building 22.4 from Source - Greenbone Community Documentation for some more details and background about the feed synchronization.