Why did my Facebook for HTC Sense stop working after the update and how can I get it working again?

A

AC Question

I downloaded an auto-update to my HTC One M7 today, but when phone restarted after update, the inbuilt Facebook app (Facebook for HTC Sense) simply DISAPPEARED. The status widget totally disappeared from the desktop, from widgets, from list of apps. It is still on the phone, though, because it is listed in Settings > Apps > All, but it won't work.

I tried clearing up the catche there, but it didn't make a difference.

Downloaded FB app but it ain't that good, I'd like to get back my FB for HTC Sense. Anyone any ideas...?