I am running WP 3.9.2 multisite, and I've tried several times to complete a scan but I get this:
Scan Engine Error: Looks like the Wordfence database tables have been deleted. You can fix this by de-activating and re-activating the Wordfence plugin from your Plugins menu.
Deactivating/activating doesnt seem to fix this.
What else could I try? I changed execution times and gave more ram, but still cant finish a scan.