All of a sudden, I can't launch Sonar.  Well, to be accurate, I can launch the app for the purposes of accessing Preferences, etc., but can't start or load a project.  When this is attempted, Sonar goes into an infinite initialization loop, flashing this pop-up message rapidly, over and over again:
 

Generic Low Latency ASIO Driver
Record 03+04 (Lynx AES16)
Checking 2 Channels, 96000 SPS, 16 BPS ...

 
For the record, I use Lynx' custom driver - not the generic driver.  Furthermore, I've been operating at 24 bits forever.  Sonar's Preferences verify this.  So, I'm not sure what any of this means.
 
I haven't made any significant changes to my workstation, other than installation/update of a few plugins from Waves and Slate (verified to be working fine in other audio apps).  Also, I see Windows installed a few updates.
 
This occurred while running Sonar 2016.08.  Hoping that it would fix the problem, I installed the 2016.09 update, but this had no effect.
 
Any ideas?

did you try rolling back using Command Center (rolling back to 2016.07) to see if this fixed the problem ?
 
And what Windows ? 98 ? XP ? 7 ?

Resort Records
 
I haven't made any significant changes to my workstation, other than installation/update of a few plugins from Waves and Slate (verified to be working fine in other audio apps).  Also, I see Windows installed a few updates.
 
Any ideas?

I think you're on the right track here. In my experience, when problems suddenly/unexpectedly happen, it's often due to a recent change. I think about what has changed and roll back one step at a time, testing along the way.

Try re-installing the Lynx drivers. Windows updates sometimes require re-installing drivers.

Anderton
Try re-installing the Lynx drivers. Windows updates sometimes require re-installing drivers.

 This if you recently got the Win 10 Anniversary update.
 
I had to reinstall my RME drivers.

I am indeed on Windows 10.  I'll give it a shot.
 
Man, I hate automatic updates; so much so, in fact, that I employed some workarounds to defeat Windows 10's mandatory updates but then the OS ultimately went a bit wonky anyways.  I spent weeks with MS support troubleshooting, repairing, etc., and never found the culprit.  So, I re-installed everything from scratch and stuck to the script.  Damned if you do, damned if you don't....
 

i have disabled windows update by simply doing
control panel/administrative tools/services/scroll down to windows update, right click-disable
all my pc's and laptops are still on v1511, absolutely no issues. i always have disabled updates for windows at a certain stage since forever, never experienced any problems by doing it, and don't intend changing until if and when it appears necessary, which it has never been, and i think is unlikely to be, but you never know. i know everyone tells you to make sure windows is up to date, my experience says it isn't necessary, but if sonar happened to start skitzing out due to the fact that it is so tightly integrated into windows, but everything else continued without issue i would just drop sonar and carry on. it isn't my main daw and see's little use, so . . . . . . . ymmv of course

Initially I had no end of annoyances with win 10, so like Grim I have disabled windows auto update and run it only when I need to/have the time, and I always take a disc image beforehand. All smooth sailing now:)
 
I highly recommend this handy utility for turning off unwanted bloat in win 10:
 
http://www.thewindowsclub.com/ultimate-windows-tweaker-4-windows-10
 
 
 
 

I believe in letting the operating system checking for updates and informing you they are there for download and installation.  This is because any and all of the companies putting out software WILL do so based on a current maintenance level, so I keep mine current.
 
I have not had Sonar crash in at least nearly two years, and I think maybe all the way back to X2.
 
In any case, because software companies DO write and test with current OS maintenance, AND because Windows 10 CLEARLY intends for users to all be on the same page with maintenance, I do not advocate trying to disable the maintenance.
 
I DO, however, believe that the USER should decide when to allow the maintenance to be installed, and I always shoot for the wee hours of the morning.  I NEVER want to have to wait on a Windows restart to finish applying a bunch of maintenance, as I frequently have people with me when I am working in Sonar, and don't want to make them wait.
 
Bob Bone
 

I would also like to add that Windows 10 maintenance seems to jack up settings I had previously changed to my liking, such as Power Plan settings.  Because it sometimes RESETS changes to those settings I have made, I take a few minutes every week or two and review those settings, to make sure they are the way I had changed them and saved them.  I think it is completely irresponsible of Windows maintenance to reset settings changes without any sort of choice or notification in the matter.
 
Whenever I DO run across instances of the above, I DO utter a nice GRRRRR!
 
Lastly - I religiously create System Restore Points any time system changes are made, so that I can quickly undo any maintenance changes that jack up programs like Sonar.
 
Bob Bone