Frustrating Situation

I have been using Audacity for quite a while now without a hitch. But recently, after I installed an update, I can no longer record as usual. I hit the ‘record’ button, and nothing happens. The line doesn’t move, and there are no wave patterns, yet it says that it’s recording. I stop it, and try to play back, but of course, there’s nothing to play back. What am I doing wrong? Will someone please help?!

Perhaps you have activated Transport > Transport Options > Sound Activated Recording