What have you done?
WelI have supplied all the advice I can there's not much else I can do without clear feedback.

Cheers..

it does make one wonder, with audio driver handling being such a low-level requirement in any daw, what could have changed between versions in the way the daw handles the driver, what was wrong with the x3 implementation? maybe someone from cakewalk could comment what changes were made?

Are both versions of Sonar configured the same as far as driver mode and hardware assignments? Maybe Sonar Plat is configured different?

All Software has dependencies. It's a complex scenario but please take it as a given that bugs in drivers can be exposed in later versions. This X3 thing is a total red herring you need to look at the actual issue in front of you. Quadcapture issues keep cropping up over and over again this isn't old ground. The issue is to do with the interface itself. Let's not distract the OP from this.

learn how to do basic troubleshooting, doktor - whether it turns out to be the driver or sonar or something else, one can only discover the cause through a process of elimination, so disimissing x3 right off the bat is frankly a bizarre suggestion

And what does X3 working and Platinum not working help you eliminate exactly? There is absolutely no relationship going on here they are entirely seperate codebases.

What the issue is pointing to (screaming out loud) is the interface itself (ie the error message in front of the nose), therefore the attributes around the audio interface obviously needs to be eliminated first (see my first three posts) and the settings may need to be reviewed in Sonar preferences. Other's aren't having these issues so do the math.

Doktor Avalanche
And what does X3 working and Platinum not working help you eliminate exactly? There is absolutely no relationship going on here they are entirely seperate codebases.

Really?  Even MORE Kudos to the Cakewalk team for doing a complete, ground up rewrite for the new Sonar version!!
 
 

I'm sorry that none of you understand about software dependencies.

Maybe check out this thread for more info, check Cakewalks comment and my example:
http://forum.cakewalk.com...289549&p=1&p=3

The error message and the clear symptom is the real issue, the point where the process of elimination should start, the X3 thing is a total red herring sorry. If there was a big bug in Platinum and how it handles drivers, half the forum would be screaming about the same issue by now.

I have deleted the aud.ini and the cakewalk.ini from Platinum. 
Started Platinum, did the rescan and now is working ok (worked for 3 hours with audio and midi recording, no problems)...
 
Oh well, it's ok now!
Thanks

Excellent news. Happy music making...