ASIO4ALL goes back to a time when not all hardware provided ASIO drivers on Windows PCs. Like most things Windows, use the most recent version available for your Windows Version. ASIO4ALL doesn’t change often so it’s easy to have an older version without realising it. Current version 2.14 from May 2017.

Thus a clever developer called Michael Tippach created a driver that could use the elements of the (Windows drivers Model) WDM and fool the DAW into thinking that an ASIO driver was indeed available. He also added the ability to aggregate drivers from different manufacturers for different devices as improvements over the years since 2003.

When it all works it’s great but aggregating devices with different internal clocks with drivers not originally with that design in mind is not some small feat.

It’s not a short coming of Sonar but rather this complex interweaving of software to work outside of its original purpose that can cause difficulties. But as scook said several post above, the aggregation has to occur within ASIO4ALL not inside of sonar. Even the developer acknowledges that maybe only 5 out of 6 efforts to use ASIO4ALL work successfully.
I’d advise anyone using it to actually go to the ASIO4ALL website and read some of the FAQs there to isolate any problems they’re having.
Here’s the link
http://www.asio4all.org/faq.html

mudgel
I’d advise anyone using it to actually go to the ASIO4ALL website and read some of the FAQs

That's exactly what I would advise as well.
 
It does take a bit of leg work reading up on it (how to use ASIO4ALL effectively) but it can be a life saver for someone in a jam needing to work in a DAW without a soundcard designed for digital audio recording.
 
The thing that irks me has little to do with ASIO4ALL but more the makers of hardware interfaces who resort to forcing their customers to use ASIO4ALL instead of developing a custom driver themselves. Alesis is one that comes to mind who has been known to do this in the past with the IO2 interfaces.