@Bassmanx

Bassmanx
I also just upgraded to Windows 10. I too am having troubles. In my case it seems to be buffering problems. I am getting pops and crackles even when playing a single wave file (Regardless of the buffer setting I choose). This did not happen in Windows 8.1.

I had the exact same problem!!  Revert to W7 and it vanished.

I Just resolved my issue. It turns out that Windows 10 does not like my ZOOM R16 ASIO driver. I switched to the WASAPI driver and everything works fine now. (Food for thought).

I had a UA-25EX and got rid of it because it was giving me problems. In my case it was because that interface is a USB 1.1 unit and my machine was overloading it. Try connecting the interface to different USB ports on your machine. Don't use  a USB 3 port. Before mine departed I found that it wouldn't work on a hub, it had to be connected to a USB2 port on the motherboard.
 
The software is not at fault directly and Sonar screams along with Win 10. You should also experiment with I/O buffer settings and so on. If possible try another interface and see if it clears the problem. The UA 25 is on its last legs.

ampfixer
I had a UA-25EX and got rid of it because it was giving me problems. In my case it was because that interface is a USB 1.1 unit and my machine was overloading it. Try connecting the interface to different USB ports on your machine. Don't use  a USB 3 port. Before mine departed I found that it wouldn't work on a hub, it had to be connected to a USB2 port on the motherboard.

All excellent comments. A USB 1.1 interface is really an anachronism in today's systems. It's designed for low-bandwidth devices like keyboards. 
 
I highly recommend going into Device Manager and disabling (not uninstalling) all sound card/interface drivers except for the interface you're using. Then increase the I/O buffer playback size in SONAR's preferences to 256.
 
Also as a related cautionary note for others, although USB 2.0 devices should be forward compatible with USB 3.0, not all are. And just like FireWire, USB 3.0 devices want to see a chip set that makes them happy.

After installing Window 10,  I noticed I was having problems with several of my USB devices as they didn't want to work properly.  Two of them were legacy devices so I needed the older Windows 7 drivers to make them work.  
 
For all of my USB drivers, I went to the Manufacturers website and downloaded the drivers and installed them to the computer.  Upon restart, all of the USB devices that didn't want to work properly starting working just fine.  
 
I suggest getting the drivers from the Manufacturer of the device.

Many thanks for all the advice guys, and sorry its taken a few days to reply but its Christmas and the family wanted my time!
I'm going to be unavailable again until Sunday, but in the meantime with regard to the advice given:-
I've uninstalled/reinstalled the driver for my interface with no change to the situation, and I've messed around with turning advanced driver off/on the interface. Again no change.
I've also disabled all the other Audio Devices - no change!
As I mentioned in my original post, I can't revert back to Windows 7 as I have apparently gone over the time sort to revert?
What I will try next will be changing the USB plug to a different socket and changing the I/O buffer settings to 256 as suggested.
I wouldn't say I'm very good on the techie front so any advice given is great, but please try to make it idiot proof for me!!

What John said. I too have a UA-25EX and initially struggled to get it to work with Win10. It took Roland several weeks to get a driver to market, but one day I plugged it in and Win10 downloaded and installed the driver without any fuss and it's worked ever since. I think the suggestion of trying a different USB port could work too as this would force Windows to reinstall the driver, and so look for the driver again.

Hi, yeah i ran into a whole lot of headaches about that too. and i'm in 8.1!
i am so afraid of 10 it's a shame...but i heard elsewhere on the board that it's a whole lot like 8.
here's hoping:
Before fiddling with drivers that work perfectly fine with whatever else you use, it might be a good idea to go in your taskbar and hit the line out properties button(might be hidden,but it's the speaker icon thingie). go to the advanced tab and take it out of exclusive mode.
really worked for me.
before that, even closing out of the program and going back into it was a complete finagle mission.
hope that helps!

Hi all, and Happy New Year.
I'm back on SONAR again after the festivities and trying out all the recommendations given by the various comments on this thread.
The good news is that finally it looks like we have got to the bottom of the problem (hopefully). I think all the suggestions had some positive impact, but the action that seemed to nail it completely was to change USB socket from rear to front and reinstall the driver from Roland. I had indeed tried changing sockets and reinstalling the driver previously, but not changing to the front of my computer as it was less convenient. However, once installed it was clear that this was indeed the culprit. 
So thanks to John for the solution, and many thanks to all on the thread for advice. I'm now not "fed up" with SONAR but looking forward to playing around with it without glitches every five minutes! 
 
Regards to all,
 
Pete
 

May I suggest adding "solved" to the title?