This is a program bug (stack overrun), and can't be resolved by user action such as deleting aud.ini. We'll have to be patient and wait for a fix. I'm sure somebody is furiously working on it this morning.

Cannot reproduce here on Win 10 with Platinum 2016.11.  All CCC updates current, including effects.
 
Tried with a new test project, on an audio track, instrument track, and Pro Channel. 
 
My VST2 CA-2ALevelingAmplifier_64.dll shows version 2.0.1.97.
 
There appears to be two versions of this plug installed, VST2 and VST3.  Does this problem happen with both of them?  I've tried both.  Very stable here.

Did you reboot the PC after updating Sonar?  I noticed other drag and drop issues with Sonar after updating, which were resolved with a reboot.
 

Tried multiple reboots/resets/rescans. 
 
Did some basic O/S housekeeping -just to make sure- including;
 
> System File Check (sfc /scannow)
    - No integrity issues reported.
 
> Checked on latest MS Visual C++ redistros
    - There are newer ones, d/l both from MS site and updated.
       Control Panel shows them both updated -but- replacing the earlier versions listed. 
Was:
   - "MS Visual C++ 2015 Redistributable (x86) - 14.0.23026"
   - "MS Visual C++ 2015 Redistributable (x64) - 14.0.23918"
Now only showing: 
   - "MS Visual C++ 2015 Redistributable (x86) - 14.0.24215"
   - "MS Visual C++ 2015 Redistributable (x64) - 14.0.24215"
 
If there are dependencies on the earlier ones, might be hosed. 
....
Did a Regedit and manually deleted -all- references to CA2A.
 
....
Opened the test project and ran VST Scan again
   - Throws "Runtime Error!" when trying to scan both the old LP_64 EQ and Multiband Comp
   - VST Scan crashes when it tries to scan RaptureSession_64.dll
 
....
Since my O/S seems to be up to par
AND
the problem is specific to Cakewalk VSTs
AND
rolling back to the previous version did NOT fix the problem
 
I am assuming there is some fundamental configuration/coding issue that is not easily resolved with the troubleshooting resources available to an end user. Will log something with the Problem Reporter. 
 
....
Had planned to get 2 mixes done today, now debating whether it's worth trying to rebuild the FX chains for some fairly large projects or rollback further. Given the unsuccessful System Restore tried by @gmp, I'm not confident this is worth the effort.
 
Can make time to try any other expert suggestions, otherwise I'll be digging through the mix to replace instances of CA2A with the UAD LA2A and rebuilding it.
 
 
 
 
 
 
 
 
 
 
 
 
 
 

The VST scan issue might be a clue.  There was an old trick, not sure if it still applies, but running Sonar as Administrator and re-scanning the VST's fixed some folk's problems.

Apparently not specific to CA-2A. I just got the same exception opening a project that contained Rapture. As before, the project opened OK the second time.
 
Faulting application name: SONARPLT.EXE, version: 22.11.0.111, time stamp: 0x583d02e6
Faulting module name: RaptureSession_64.vst3, version: 2.0.4.25, time stamp: 0x569d4005
Exception code: 0xc0000409
Fault offset: 0x00000000001d4a48
Faulting process id: 0x16ac
Faulting application start time: 0x01d24cb96d1ac728
Faulting application path: C:\Program Files\Cakewalk\SONAR Platinum\SONARPLT.EXE
Faulting module path: c:\program files\common files\vst3\Rapture Session\RaptureSession_64.vst3
 
One obvious commonality is both faulting plugins were VST3.

Confirming the problem after deleting all entries in the registry and reinstalling from CCC.
 
1. Regedit/Delete all entries for CA2A (3x)
2. Reboot
3. Rollback to 2016.10
4. Reboot
5. Open Test Project
    - confirmed CA2A missing
6. Reinstall CA2A from CCC
7. Open Test Project
    - confirmed CA2A missing
8. Run VST Scan | Rescan Failed Plug-ins" checked
    a. Hangs on "Scanning CA-2ALevellingAmplifier_64.dll"
    b. Close toast
9. Run VST Scan | Rescan Failed Plug-ins" checked
    a. Completes scan, shows 2 new found
10. Able to open test project. all good. 
11. Able to open client project. all good
12. Reboot 
13. Project CRASHES. 
....
Why is VST Scan is having problems with what appears to be a clean and approved install of Cakewalk products?
Why is rollback NOT solving the problem?
....
I'm back to getting a mix done now that I can open the client project (as long as I don't reboot ....)
 
No time for further troubleshooting. Will file a Problem Report when I have time, but may not happen until next week.
 
 
 
 

Jackson, I discovered something that may help you. In my post

CA-2A + LP 64 EQ causing Runtime errors

 about the same problem, I was mistaken about something. Let me give you the complete story.
 
I've used 2016.09 since it came out and has been one of the best versions for me. I tried 2016.10 on 11/8 and saved an image file. After lots of little problems with it, on 11/17 I reverted back to a 2016.09 image.
 
This problem with CA-2A and LP-64 EQ happened yesterday about the same time yours did - now is that weird? You were using 2016.11, I was using 2016.09  I intended to revert back to my 2016.09 image and mistakenly reverted back to the 2016.10 image and I still had the crashing with CA-2A and LP-64 EQ. Uninstalling and reinstalling CA-2A fixed that plugin.
 
Last night I discovered what I did and first saved an image of this problem and then this time reverted to 2016.09. Well thankfully all the CA-2A and LP-64 EQ problems are gone without any reinstalling or uninstalling.
 
So maybe you should try to revert back to 2016.09, maybe with System Restore if you don’t have an image file, since reverting to 2016.10 didn’t work for me. Maybe 2016.09 is better with the VST scan. By the way I don’t have auto updates on. I only do WIN updates right before I update Platinum.

I have been using cakewalk for years. And to me it's becoming actually more unstable. Now I have the same problem. It crashes when I try to open a project. I did however get it to open and run. I loaded a WDM driver instead of ASIO. This is not may preference and simply will not work for me. If you find the true root to the problem I would be very thankful for any advice you can give me.

I agree that these last five versions have been taxing my CPU more and more! Now I'm getting the clicks and pops on project configurations that used to run with zero issues before. Is there any way to turn back several versions?