i just saw an update for the app pushed to my device today. did you get this latest update?
in the facebook settings tab under account settings, uncheck the three options (calendar, contacts, live feed) then re check them again.tap the three dots top right and select "sync now".
if that does not work, head back in there and go to the three dots then "remove".
go into apps and swipe screen to the left to "all". scroll to facebook for htc sense and force stop.
if none of the above is working, verify this issue occurs on wifi as well as data and make sure nothing on your desktop version of facebook has been changed.
this is really a simple thing to fix, but if you have some other app disabled or something interfering, its going to be an uphill battle to try and fix over the internet.