Sorry. I replied to your post a while ago but it was automatically deleted by Akismet (which is a forum spam service which removes posts if the user edits them too many times). I asked the admin to retrieve it and post it back in this thread, and he kindly did so, but it appeared before your last post, not after. Just in case you didn't see that post.
(I also sent you a PM about this at the time, in case it could help.)

I saw the deletes and restored the last one, however; we can't change the post order.

GjB
I'll chime in because you mention Focusrite.
I don't have much experience with Firewire (I've never used it), but you might consider trying USB?
I was having the same problem as Tripecac on this thread where (for me) since the Windows 10 Creators Update, audio was dropping out every 45 seconds or so (in everything, YouTube, MP3s, etc.).
Since the Creators Update Windows 10 seems to have an issue running the 2i4 (which is USB 2.0) through a USB 3.0 connection. All of my external connections on my PC case are USB 3.0, so I had to run the Focusrite 2i4 directly to the USB 2.0 pins on the motherboard and the audio dropout issue in Windows was fixed instantly.
 
Before that, about a year ago, Focusrite also sent me a driver to get my Focusrite to work in Windows 10, just before they updated to their latest USB driver version.
 
When you say new build, I wonder if you have recently upgraded to Windows 10?
Please note that the Windows 10 Fall Creators Update is due in just 2 days on the 17th of this month, so it might be good to do a fresh ISO install of that when it's available, in which case holding off until then could be a good thing.. 

Hi, I got your PM.  I do have another Focusrite audio interface (Scarlett 2i2) which uses a USB 2.0 connection instead of Firewire.  The reason I'm using the interface with a Firewire connection is because I read that Firewire offers faster speeds than a USB 2.0 connection.  I never had any problems using it, so maybe I'll try that again to see if it works any better. Thanks for the suggestion.

So far, today, I've still had no issues yet.  And I've been pushing it pretty hard.  So I'm not sure what's causing the problems I've been having over the past couple of weeks.

Any hints that your problems may be project specific? It's strange that you can push it one day but not the other ...

Rob[atSound-Rehab]
Any hints that your problems may be project specific? It's strange that you can push it one day but not the other ...

No, I went back to the same project as yesterday, and tried to do the exact same things I was doing before and when it crashed.  That's what makes me think it's a driver issue within Windows, my plugins, or my hardware.
It could have been something as simple as Bitdefender doing a virus scan (which I'm now turning off when I run Sonar).  But until the next problem happens, I'm just guessing.

Leee
It could have been something as simple as Bitdefender doing a virus scan (which I'm now turning off when I run Sonar).  But until the next problem happens, I'm just guessing.

AV often gets in the way of software packages that needs lots of CPU power and fast access to drives.  Best practice for DAWs is to keep AV off or use a very light weight one at your own risk ... if you do the later, make sure you exclude virtually all processes that relate to DAW functionality and all directories that you need to access (projects, samples, plug-ins, etc.)

I just had another Audio Engine stoppage.  Again, the project was small and simple.  Three VSTi's active: Superior Drums 3, Orange Tree Samples guitar, and Scarbee Bass (which is what I was playing at the time). No efx inserted anywhere.

I decided to look at my Windows sound configuration and noticed the computer's digital audio (S/PDIF) High Definition device was reinstalled again (after I uninstalled it on 10/5/17).  If you look at the screenshot, you'll see that this device was reinstalled again 4 days ago and enabled, "Ready" (under the Playback tab). But it's not my default device, which is my Saffire Audio device. 

I disabled it once again just now.  Is there any chance that THIS could be causing the Audio Engine to stop?

(Windows 10) Control Panel - System - Advanced System Settings - Hardware (tab) - Device Installation Settings -  Do you want to automatically download manufacturers' apps and custom icons available for your devices? - Check No.
 
This will stop Windows 10 from installing drivers over the top of the ones you are manually installing and trying to use.
So, if Windows has reinstalled drivers which you don't want, do the above and then manually reinstall your preferred driver (and reboot). (Also, if you don't use some devices, then you can safely disable them to limit potential compatibility issues.)

Disable anything you do not use. There have been a couple of threads about disabling HDMI devices. CraigA recommends disabling them. for example http://forum.cakewalk.com/FindPost/3654214
 

Thanks GjB, I'll go to the advanced settings and check NO for automatic downloads for manufacture apps and drivers..

scook
Disable anything you do not use. There have been a couple of threads about disabling HDMI devices. CraigA recommends disabling them. for example http://forum.cakewalk.com/FindPost/3654214
 

As I said, I not only had the device disabled, but I completely uninstalled the driver!  Windows must have reinstalled it and enabled it during the last update.

I sure hope that this is the problem!!!  After uninstalling it, I was playing and recording in the same project that I was using when the Audio Engine stopped.  So far I've been working on it for a half hour.... so far so good.