I am a long time sonar user. I have platinum. IN the last month or so - not sure if this is tied to lexington or not - when I record a waveform like guitar or vocals, when I hit the space bar to stop recording, the newly recorded track instantly disappears. Trying undo does nothing.
 
It happens maybe 20% of the time.
 
If I am recording two tracks at the same time, as I often do, one of the tracks survives, while the other one "puff!".. gone. (Not the whole track just whatever was being recorded this time).
 
 Anyone else experience this?
 
Rick
 

That does sound very odd.  Is it possible you're recording in comp mode and when you hit the space bar, you only see the resulting take? 
 
 

I have had it happen but only with a M Audio delta 44 interface. what is your setup?

I had that problem when recording from a vsti synth last week.
I recorded a voice on one track then dragged that audio data to a new strip for safe keeping then changed the patch and recorded again. The wav form showed up as we went then upon stop the wave disappeared.
 
This happened over and over then for no explainable reason It appeared and played so I moved on.
This was my first attempt at synth recording but that's what happened.
 
dang useful feature though.

Karma - I record using the Sound on Sound option... and I did check any take lanes.
 
I have - and have had for a long time - a creative labs sound card - I forget which one but it was teh high end $200 jobber for audio work and has asio drivers which is what I use.  I've had the card now a couple of years and have only started seeing this in the last month or so.  I upgraded to win 10 a number of months ago.. I can't think of anything in the last couple of months other than I purchased Kramer Master Tape VST and applied the Lexington Patch.
 
I tried with all VST's off, and I have tried at different bit rates. Still happens periodically enough that my neighbor probably hears my screams of horror... :-)
 
Well at least its good to hear that I have some company...
 
Rick
 

So the tracks are there, only waveform pictures missing?
 
I can't see how the audio interface could have anything to do with disappearing waveforms, tracks or audio. It has no control over creating or deleting  SONARs tracks, creating the waveform pictures etc. , AFAIK.
The disappearing of the waveform image does not automatically mean that the audio has disappeared. Did you try playback and confirm that the audio is gone?
 
The waveform is just a picture indipendently produced, it's not necessary for recording. "Redraw waveform" or emptying the Picture cache file may help, depending on the case. SONAR creates new pictures in Picture cache By restart.