I recently went back to a project file I worked on last year and I add a new track and I arm it and then press record and nothing gets recorded. The music plays but no information gets recorded onto the project. What's going on. I tried saving it as a new file but that didn't help. I thought about moving each individual track, but that too hard because I'm using multiple sends and many effects. Someone please help me!

Same answer as to your other question. You must give the basic info to make answering possible. How exatly are you recording and what. Was the track armed before hitting "R"?

Ok. I'm recording using a microphone. The mic is plugged into an Alesis MultiMix4 USB mixer which (obviously is plugged into my computer. What other info do you need? Yes, the track was armed. It's only in this specific project file that its a problem. When I create a new project file or open any other project file, I'm able to record with no problems. Over here, I press record and it starts playing as if its recording, but nothing gets "written down".

So, you have double checked that all the settings in the problem project are exactly as in the ones that allow normal recording?

You're not accidentally trying to record on a MIDI-track? You see level meters moving on the target audio track? Is there a clip with straight line created when you do the recording or does the track stay empty?