MC-6 has worked fine for months. I record midi tracks, insert an audio track, then record the midi to audio. Suddenly the audio track is dead. When I press its Record button it lights up but when I press R the cursor does not move. And when I click the Record button again it will not go off. The track is dead. The midi tracks work fine. 
 
Things I've tried:
Delete the audio track then insert a new one.
Close and reopen the project.
Open a new project (it had the same issue).
Disconnect and reconnect the USB devices: mixer, sound module, midi controller keyboard.
Reboot laptop.
Reinstall Cakewalk.
 
Any ideas would be appreciated.
 

Some more info on your system might help us help you.
Go to your forum profile and enter in your signature what program you're using, your operating system and whether it's 32- or 64-bit, and what audio interface or sound card you're using. Then click the Save button at the bottom.
This will keep us from having to ask the same questions each time you have a problem.
 
Now, why are you inserting an audio track and how do you record a MIDI track to it? An easier, quicker way is to Bounce the synth to audio, which will render the MIDI/soft synth to a new audio track.

Greg,
I entered the info. The comment I entered shows on my proflle but I don't see the so-called signature info that describes my toys. I don't know where to click.

Ahh! Just as I submitted the above, the toys appeared. How clever!
 

I see. You're not using software synthesizers.
So is this how you work; record MIDI with the controller into MC 6, output MIDI to Ketron from computer, Ketron audio out to Behringer which is connected to the computer via USB?
What are your track input settings?
What are your settings in Options>Audio or View> Preferences>Audio?

Yes. My production path is as you have described. Since MC-6 has low quality MP3, I export the audio as a WAVE then use NCH Switch to convert to MP3. And these files I use as backing tracks for live piano.
 
My settings are the same as when everything worked properly. They are:
Audio Devices > Driver Mode: Asio, Playback Device: Behringer
MIDI Devices > Inputs: Roland A-49, Outputs: Ketron.
 
I still have 58GB of free space.
 

Greg's asking about your TRACK input and OUTPUT settings, not the AUDIO and MIDI PREFERENCES settings in MC.
 
look at your MIDI TRACK PROPERTIES. if you don't have ALL properties showing, make sure you enable that first by clicking on the little 4 squares icon near the top of the tracks on the left side.  then pull down enough of your track to see all of the properties.

Thanks, Beagle. Those properties indicate volume, pan, automation read, and other settings. They reflect adjustments which I make in Console view but that seems remote from the problem because my MIDI tracks record and playback properly. But RECORD on the audio track is dead. As a work-around, I'm recording from the mixer to an outboard digital recorder which I'll carry to a friend's house who can record them onto Audacity, export them as WAVES, and slip those into my thumb drive to bring home for conversion to MP3. What a mess, but it will keep me going.
 
The Logical Guess
My setup has worked properly by the interchange between (1) laptop, (2) operating system, (3) Cakewalk, (4) controller, (5) sound module, and (6) mixer. Since the song will still play from the midi tracks, and since I reinstalled Cakewalk, it seems the culprit has to be the computer. Its Windows 10 updates often fail to install. Nothing else makes sense. Whatdaya think?

Updates are infamous for changing things adversely, including track input/output settings.
Did you check that your audio tracks are set to the correct input?