I had a project that used asio4all.  Its performance was bad, so I uninstalled it.
 
Opened the project and changed driver system to WDM/KS.
 
Sonar profiled the devices I have attached to the computer (interface and mfx).
 
Tried to play audio.  Crash.
 
Open sonar again.  Try to play audio.  White screen.  Crash.
 
Open sonar again, create new project.  Open preferences.  White screen.  Crash.
 
times infinity.
 
What do?  Sonar is completely broken.  Won't run.

Can your sound card do native asio?
 
I had the opposite problem with an old audio card and win10. When in ASIO mode sonar would crash on startup. I tried WDM and that fixed it for me.
 
 

Looking at your spec in the footer you list your audio interface as the RME UFX which has it's own ASIO driver. Is there a reason you are not using the RME ASIO driver? 
 
I have the same unit and have the drivers installed on 3 different machines and they are rock solid. 

karhide
Looking at your spec in the footer you list your audio interface as the RME UFX which has it's own ASIO driver. Is there a reason you are not using the RME ASIO driver? 
 
I have the same unit and have the drivers installed on 3 different machines and they are rock solid. 

I had glanced at the original post as well, and had the same thought.
 
I have only seen a small number of posts where for a particular audio interface ASIO drivers weren't the best choice, so I too am wondering why the RME ASIO drivers are not being used.
 
Is Windows maintenance completely up to date?  What about all the drivers for the computer?
It seems like if you are crashing like this, it would be some maintenance deficiency, or a driver problem, so I would start there.
 
I suggest you also look at the Windows Event Viewer, and check for errors being logged at the system level, at around the same time Sonar has crashed.
 
I also bought a pretty inexpensive ($50) program called WhoCrashed, which will analyze your system errors and dumps and build a nice report with lots of details on why things crashed.  There may be some freeware that will do that.  I believe LatencyMon will provide some information that might also be of some use, and that one is freeware that is really nicely built.
 
IF there is some sort of conflict between devices, you can check the System Information report for your computer.  Hit the Windows Start button, and type in msinfo32.exe and hit Enter.  This launches System Information - now expand the Hardware Resources tab, then click on Conflicts/Sharing, and give it a short amount of time to refresh its information for you, and it will present information on both IRQ sharing and on any detected Conflicts between devices.
 
Bob Bone
 

Try renaming your aud.ini file to something like aud.old.  This will force sonar to re-profile your device(s).  I know you did this once, but it may work by changing the name of the file.