On the January 1st 2012 Facebook Markup Language took one step closer to being left on the shelf to gather dust like the ZX Spectrum as Facebook ceases to support its proprietary mark-up language.
On June 1st 2012 all FBML applications will no longer work so any businesses currently making use of these should take heed and make preparations well in advance.
Most commonly website owners, developers and designers have used Static FBML tabs to create custom pages on fan pages. You’ll be able to identify additional pages making use of the Static FBML App by the little grey symbol highlighted in Fig.1. below.
Those should be transitioned to making use of iframe canvas pages in its place. Simplistically a canvas page tab will be a seperate page on a web server that you control pulled into a 520px wide iframe on your Facebook fan page.
See the canvas tutorial for further guidance or contact Sumobaby to discuss helping you make these changes in time.
Facebook statement
We are deprecating FBML. On Jan 1, 2012: FBML will no longer be supported on Platform. June 1, 2012: FBML apps will no longer work. All FBML endpoints are removed. If you are building a new application on Facebook.com, please implement your application using HTML, JavaScript and CSS. You can use our JavaScript SDK and Social Plugins to embedded many of the same social features available in FBML.