I get this message when opening a one specific project. But I can't locate the clip or "region" in question. All my audio files have the waveform drawn, there are no clips with just a line. The project is only 1:08 minutes long with only nine tracks of audio and about the same number of midi tracks. I wonder why Sonar doesn't tell you which clip or track this corrupt region is in. Anyone having a similar issue?

Habe you checked the take lanes? Mabe the corrupted clip is under another clip and is hidden. Happend to me once.

And I found a post in the forum related to your issue:
http://forum.cakewalk.com/A-corrupt-audio-region-was-detected-and-padded-with-silence-m1379142.aspx
 

Hi Andy, I didn't use take lanes and I'd already seen the link above my friend. No success😞

There could be other audio data that is known to the project but doesn't appear on the time line. For example, slip-edited clips could represent audio data somewhere in the middle of a file, where the "corrupted" part of the file has been trimmed away from the track. Also, tracks that have been frozen have audio files standing by for unfreezing that doesn't show on the track.