brundlefly
Good suggestion, Jonesey. There have been a number of cases where SONAR 2015 didn't like the AUD.INI settings it inherited from an earlier release. Especially suspect in this case since the old AUD.INI will have all the E-MU config stuff in it.

I agree, this is likely. Deleting/re-building the AUD.INI file may be the simplest solution.
 
I've often found that installing a new program will be affected by a "hangover" from an older program if the older program isn't removed. Many pieces of software uninstall older versions as an inherent part of the process of installing a new version.
 
The closer a new installation can come to a truly new installation, the better. IIRC there's a way to open SONAR that deletes the personalizations and starts fresh, but don't remember it offhand.

Also...weren't there some issues with older templates not loading correctly, especially complex ones? Sorry I can't be more specific, I don't have a photographic memory for all these things...
 
I really think a lot of the reason why my system works so well is because it's very close to pure 64-bit - OS, programs, plug-ins.

Craig - I completely concur on the stability of a Sonar environment that is as purely 64-bit with all plugins, as possible, or a completely 32-bit install.  Either of these two setups have worked flawlessly for me, BUT until I had deliberately removed all 3rd-party 32-bit plugins from my 64-bit Sonar search paths, I did have increasingly flaky problems.
 
You might also consider doing a Reset AND a Full Re-scan of plugins, in addition to deleting the Aud.ini file and letting Sonar create a nice shiny new one for you.
 
Bob Bone