Hang trying to load CWP files after changing interface

I don't know if I should submit a bug report on this, but I figure it must be such a common thing that maybe somebody in the community can help.  I am running Sonar Artist with the 2016.05 update 1, although this problem goes back at least a few months.
 
A couple of months ago I switched from using the WDM drivers to ASIO for my UltraLite MK3 in Sonar.  I soon found that I couldn't open any project files that had been saved with the WDM drivers unless I first switched back to WDM, opened, and then switched back.  When I say "couldn't open", I mean that Sonar would hang and I would have to kill off Sonar.  Opening in "safe mode" resulted in a question about plugins, but then it would still hang.  Regardless, I had a work around and I just went forward.
 
Now I am experimenting with a new UltraLite AVB using its ASIO drivers.  When I open a file that was saved with the MK3 (and different device names), I get a "Missing Audio Devices" popup asking me to map to new devices, but Sonar is frozen.  I can't select anything or click a button.  Again, I have to kill off Sonar.  Safe mode doesn't make a difference.
 
I don't know if these two issues are related, but I would like to know if other people have experienced this.
 
Thanks in advance -- I have lots of projects that I am working on and not sure how to proceed.
 
 

If it's a bug it must be new as I have used 4 different interfaces over time and Sonar certainly never has frozen. Projects done on my long gone M Audio fast track the Outputs get changed from 1/2 to SPDIF so some weird reason. 
 
I record live gigs to my laptop in WDM mode using my Tascam us1641 then dump the projects to my main DAW which uses my Scarlett 6i6 in ASIO without any issues at all. All that happens is the inputs change from all the multi channels to scarlett stereo 1. The outputs seems to stay 1/2 with this combo of interfaces. 
 

Try renaming "AUD.INI".

Audio Driver settings are stored in that .ini file, and SONAR will build a new AUD.INI based on the settings of your current audio interface upon the first start.

AUD.INI is located in
C:\Users\...\AppData\Roaming\Cakewalk\SONAR Platinum
 

Thanks for the suggestions.
 
I did try renaming Aud.ini with no luck.  
 
I will look more into HD Audio (which my mother board has), but all of those drivers are disabled and have been throughout.
 
I went ahead and installed my other interface and drivers, and yes, my projects open just fine.   I may need to remap all audio to "none" or to the new interface and see if that works.
 
Don't feel like I really have a solution and can't really take the time to reinstall Windows from scratch just to see if the "waxy buildup" of Windows is part of the problem.  

Before re-installing SONAR, try a full repersonalization by holding down CTRL and SHIFT while opening SONAR. This will overwrite files in your user directory and reset some of the registry settings back to default. If you have custom files you want to save make a copy of your user directory first. The user directory in this case is "%appdata%\Cakewalk\SONAR Artist." Although a clean reinstall of SONAR is pretty quick. I would be surprised if either makes a difference in this case. May also want to try a roll back before clean reinstall.

So for those interested, I have not had a chance to try to fix this on my main machine, but did get the drivers and new interface working on a laptop.  There I have no problems opening my old audio files.  So, I think I'm left with a clean Windows install, and possibly a dual boot as well to keep a DAW-only clean install.
 

Well, I did have some luck today.  I installed a separate instance of Windows 10 on the same machine (for dual boot).  This way I could see if it worked on a clean system without committing to a full reinstallation of everything. Sure enough, it works just as expected.  When I open a file mapped to the old interface, I get the remapping dialog and after that it works fine.  So after all it does seem like some problem with my installation of Windows (and software, drivers, etc), and not Sonar.