Anderton
Everything worked as expected. Because I can't get it to misbehave, I can't tell you how to avoid having it misbehave.
 
The only suggestions I have are:

• Try changing Melodyne to the Percussion algorithm. 
• I noticed as it was doing its thing that the first screen shows "mixing down audio." Maybe try using half of the stereo pair?

 
Thanks a lot for trying, much appreciated. I do wonder whether it makes a difference what melodyne version is installed or is this drag to timeline fully integrated into Sonar so that it also works without any Melodyne installed?
 
I stayed at Melodyne 2.1.2 and so far have not bothered to upgrade as version 2 does the job.
 

Anderton
Next bug: if you make the mistake to drag the "track waveform preview" which is the combined display of various comped takes of e.g. 4 takes, the ARA analysis is performed on every (!) take and not just the one that is not muted. you can actually watch it cycle through all takes, bouncing muted takes internally to silence and then trying to ARA analyse it ...
 
This probably isn't a bug. Remember that although Melodyne is integrated with SONAR via ARA, it is not part of SONAR. When you drag the parent track, you're dragging all the Take Lanes. Melodyne probably doesn't know which ones are muted and which ones aren't. This would need to be a feature request, but for now the solution is don't make the mistake of dragging a parent track with muted comp tracks into the timeline. 

Now being aware of it, I can flatten comp and drag that to the timeline ... or bounce to new track for safety ... somehow it seemed logical to me that Sonar should only pass what's audible for analysis ...

Rob[atSound-Rehab]
I stayed at Melodyne 2.1.2 and so far have not bothered to upgrade as version 2 does the job.

I wish you had included that information earlier, I think that's your answer. I tested using 4 Essential although it also works with 4 Studio. 

Rob[atSound-Rehab]
I stayed at Melodyne 2.1.2 and so far have not bothered to upgrade as version 2 does the job.

The tempo extraction is done by Melodyne. Not some "internal" one, just the one you call with ARA. With the same default settings (f.e. it can be in polyphonic mode). There was many reports about crashing melodyne and there was many fixed mentioned in updates. But obviously all these fixes are for the latest version, so I do not think any crash reports about 2.x are going to be investigated (which is also logical since basic version delivered with Sonar can be upgraded for free).

Rob[atSound-Rehab]
I stayed at Melodyne 2.1.2 and so far have not bothered to upgrade as version 2 does the job.

My test was run with Melodyne 4.1.0.001.   Celemony significantly improved the tempo detection capabilities in version 4 and I believe the latest SONAR ARA improvements were targeted at version 4.
 
-- Ron

Platinum 2016.11 was updated with Melodyne Essential 4.1, as well as with Melodyne Studio 4.1 Multitrack Support.
 
http://www.cakewalk.com/P...ONAR/Whats-New#2016.12

Thanks. Now this is a reason to justify the upgrade. So far I was under the impression that the ARA stuff implemented in Sonar is independent of whether there is Melodyne / which Melodyne version there is ...

Rob[atSound-Rehab]
Thanks. Now this is a reason to justify the upgrade. So far I was under the impression that the ARA stuff implemented in Sonar is independent of whether there is Melodyne / which Melodyne version there is ...

It can be (e.g., Drum Replacer) but the tempo-shifting aspect depends on Melodyne. Also note that in some cases you may need to switch Melodyne to Percussion mode to accommodate music with wild tempo swings.

OK, thanks for all this help in the thread.
 
The issue was resolved by completely uninstalling Melodyne, upgrading to Melodyne 4.1 and reinstalling Melodyne.
 
Apparently there must have been some sort of confusion between a Melodyne 4.1 runtime version and the previously installed Melodyne version, which was still at 2.1.2. Now everything is at 4.1 and all symptoms described are gone. Tempo detection also works much better.