After X-Force license has been applied, rule sets, SDKs, and Feeds are not present.
Even after following and verifying the FAQ (http://www-01.ibm.com/support/docview.wss?uid=swg21701213) it doesn't work.
Resolving the problem:
On QRadar 7.2.6, X-Force rules are not installed by design in 7.2.6. You will have to run the following command from ssh session logged as root: