I had to uninstall EZ Drummer 2 and EZ Drummer 1 and then reinstall 1 in order to get Sonar working again.  Before I uninstalled, a copy of a project was corrupted and I had to revert to an earlier version.  (Yes, I had a backup, but I switched to EZ D 2 and the problem did not surface until I had saved to both locations.)
 
Toontrack maintains there is an interaction problem with Sonar's audio outputs, but they claim they are waiting on Cakewalk to respond.
 
Does anyone have additional information?  If we are stuck in a loop of Toontrack and Cakewalk pointing at each other, I am going to get a refund for EZ D 2.  Toontrack might say. "It works with other DAWS" but Cakewalk could say (and I would agree) that all other VIs work with Sonar, including the first EZ Drummer.
 

Seems to be only Sonar has this issue and some collaborative effort is needed to resolve it... it would be appreciated if Cakewalk and Toontrack worked this out.

I know complex software issues take time, but the stone-walling is not good.  Updates would keep everyone calm.
 
Toontrack does not want to lose Sonar customers.  That's a lot of people.

I took the one SONAR project that I had using EZdrummer1, saved it as another name and then changed the messed up routing on two softsynths.  I had to split the instrument tracks for both of them.  One of the softsynth tracks referred to a version that I no longer had so I inserted a new soft synth and routed the midi to the new synth tracks.  Took me maybe 5 minutes.   So, are you saying that  sort of thing will not fix your tracks?
 
Based on the release dates of past SONAR versions, I'd be willing to bet that the Cakewalk team are hot and heavy into preparing SONAR X4 for release candidate versions so they can test it before going into gold status.  They probably want to deal with a 3rd party soft synth issue at this time like they want a hole in the head.  I'd be willing to also predict that SONAR X4 won't have this problem.
 
TT went to work immediately on the multi channel crash issue and the recent update fixed that.  They are waiting on CW to get back to them and if there is anything on the TT side of things that can be worked out to make SONAR happy (based on what I've seen) they'll be right on it.  But with every other DAW host picking up the new, extra 8 stereo outputs just fine it looks suspiciously like the issue is with the host.  But even that has a quick workaround. 

Is there a problem with the word sus-picious-ly on this forum?

Language filters are inherently incapable of understanding context or nuance. Think of them as being somewhat like politicians, but less likely to start wars.

Thanks, Mod Bod, but it is more than routing.  I can split instrument tracks and fix that.  Other problems:
 
1-Synths will not freeze correctly.
2-Frozen synths cannot be unfrozen to fix routing (or to edit).
3-All audio is suddenly lost and cannot be restored.  Before this happens, you may first lose audio on some soft synths.
 
Sweetwater technicians were able to replicate these problems reliably when following the scenarios I sent them.
 
If you upgrade to EZ Drummer 2 and never open it in a project that was created with EZ D 1, you may avoid the problem on that particular project; but of course, that means no drum editing and no ability to use the new drum kits or features on an existing project.
 
I do think there is something weird about Sonar, because sometimes routing messes up on its own without EZ D's help; but EZ D 2 causes those other more serious issues.
 
If Sonar ignores an issue with the most popular virtual drummer in the world because they are preparing a new release, I think they are making a big mistake.  Most people with jobs can't focus only on one thing and shut everything else down.

My only gripe with Toontrack is their moderators who answer posts at the Toontrack forums.  Hard to be any more rude in many cases or they totally interpret the question wrong and come back with an answer out of left field.
 
Toontrack does seem to be taking their time on the Superior update to use the EZD2 kits within Superior.

mixmkr, you are right. The Toontrack forum is definitely not up to the gold standard we are used to here. Example: My simple post about a key map waited on moderation two weeks and then disappeared.

konradh
If Sonar ignores an issue with the most popular virtual drummer in the world because they are preparing a new release, I think they are making a big mistake.

Unfortunately it's not that simple. We all know Sonar works with virtual instruments, including ones that have multiple outputs, but here we have one instrument where there's some kind of issue. Regardless of whether it's due to Toontrack not recognizing Sonar properly or the reverse, having to change code to accommodate one instrument risks breaking the code for instruments that do work. A lot of QCing would have to be done before a patch could be released.
 
Remember the POD Farm 2 issue? It had problems with X3 because X3 changed the plug-in handling to follow protocol more strictly. When Cakewalk came up with a workaround in Sonar to accommodate POD Farm 2, it caused problems with other plug-ins that followed standard plug-in handling behavior. Eventually Sonar had to revert back to the way it was, and so you have to use a simple workaround with POD Farm 2. At least in that situation there was a satisfactory resolution.
 
IIRC a similar situation happened with Universal Audio, where Sonar made some changes to accommodate UA but then UA made some changes that didn't require the changes in Sonar any more. So when UA fixed the problem at their end, it broke the previous Sonar fix. Now everyone has it sorted out, but for a while using UA's updated OS software with Sonar was problematic.