Hmm - just when I thought it was all resolved there seems to be a new issue.  When I first loaded the Platinum demo, I was able to add different sounds from Philharmonik 2 across several tracks under the VST2 option - brilliant.  However when I went in the next day, although I can still load the sounds to tracks, I can no longer hear them.  I haven't changed any settings (of course you can't save any changes in demo mode anyway).  I am using a Focusrite Scarlett 2i2, and Platinum is recognising it.  Miroslav Philharmonik 2 is also recognising it and plays OK as a standalone.  It looks like SONAR is somehow disabling the sound interface in Philharmonik 2, although, as I say, when I first launched the demo version it worked perfectly so very puzzling.  Any ideas please?

If you load a wave file into an audio track does it play back?

Are any other of your VSTi's affected the same i.e. Dim Pro, Z3ta+?

Do you have power management disabled on your USB ports?

Thanks Wookiee (been offline for a few days).  I loaded a WAV demo file but got an error message saying 'Missing Plug-Ins'.  The following plug in - Cakewalk Analyst (Bus: 'Master') could not be found.  Of course the file did not play, but it does play in X1 Essential.  I'll do a comparison between them and see if I can find the issue.

No problem some people have a life

I would check that all your audio is configured and selected in SONAR preferences.

Did you use a supplied template?

I think the audio is configured correctly.  The device driver and device settings are correctly showing Focusrite, and I have set it to scan all the folders I previously used for X1 Essential, but I still keep getting the 'Bus Master Missing' error message when I load a WAV file.  I don't recall there being a template with the demo download, and I'm reluctant to invest in the full upgrade while this issue is outstanding.  Perhaps I can uninstall and re-install Platinum demo.

Missed your response, what Focusrite interface are you using?
 
I ask as I use a Pro 40 and previously a 26 i/o which both happily work with SONAR

Thanks - I'm using a Focusrite 2i2.  I did uninstall and re-install the Platinum trial version but it made no difference- still no sound. However I also installed a trial version of Professional and it works perfectly each time I use it, and meets my requirements, so I have now upgraded to Professional.  It look as though there may have been a bug in the Platinum trial download.  Thanks for all your help and advice with this.

Glad to hear you have it sorted, sometimes AUD.ini needs to be deleted.  This contains the configuration details for the audio side of SONAR, it gets rebuilt on startup if it is missing.  Deleting it and allowing it to be rebuilt removes any historic data that is no longer applicable.