Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
Facebook Releases iOS App Update Including Voice Messages
Facebook has just released an update to its iOS app for iPhone, iPad, and iPod touch. The new update brings the ability to send voice message and record video straight from you iOS device. The update also includes a improved Nearby tab which allows users to easily view and share their favourite places and business. Another little feature added in version 5.4 of the Facebook.app is the ability to hide users post on your news feed.