As had been announced previously, Facebook has implemented the final removal process for all old FBML apps on Facebook Pages.
Below is the Platform Status screenshot:
Here is the excerpt from Facebook.
Platform Updates: Operation Developer Love
Since last Wednesday’s update, we spotlighted NBC’s The Voice, published Early Success Stories: Shopping, Fashion and Open Graph, and published a Games Round-Up.
Breaking Changes Effective Today
Today the following changes are in effect. For more information, check out the Developer Roadmap.
Removal of FBML
FBML apps will no longer work on Platform. The “FBML Removal” migration now appears and is enabled for all apps. It will be possible to disable the migration, thereby re-enabling FBML, until July 5, 2012 when the migration and all FBML endpoints will be removed completely.
ALERT! If you are still using Facebook’s old FBML tabs for your Facebook Business Page, now is the time to make the change to a current tool like TabSite.