I'm running the latest 2016.9 release.
 
I just purchased the Waves Dorrough Meters plug.  And it's not showing up in SONAR.  I noticed after the last update that the VST scanner was under-reporting my VST plug ins, even if they were all showing (until now).  I've run the auto scan, and the scan in the plug in manager, to no avail.
 
The Dorrough meters are showing in Cubase, so I am thinking this is a SONAR problem. 
 
Any ideas/advice?  It would be most welcome.

Hi. Have you tried to do a vst reset and rescan? It comes up on my pc.
All the best.

Thanks for your reply.
 
I'd like to avoid a reset if possible, it seems a bit destructive.
 
I did try a preferences>VST>manual scan>rescan existing plugins
 
And it won't run successfully (windows reports stopped working) 
 
My plugin count from scan has actually gone down at this point.

So, I did a reset and still can't get a full scan to work.  I suppose because waves would come at the end, that's why it's not picking up the new plug. 
 
Any ideas as to how to get my scan to run successfully?

Did you perform the update released today? http://forum.cakewalk.com/FindPost/3496455
The About screen should show 22.9.2 build 42

I did run the update released today, no love.
 
I ran some more scans, and an auto scan completed successfully, except it failed on TH3 64 bit.  I removed it, and got my Dorroughs (273 plugs now, up from 93).  I got the Dorroughs, but suspect I broke TH3, which I paid for an upgrade on. 
 
I still have an issue, but would rather have the Dorroughs than Th3 at this point.  (It might be the CW version of TH3 that's broken).

Often when a plug-in stalls the scanner, after removing it and allowing the scanner to run to completion adding the plug-in back will get the scanner to pick up the offending plug-in again.

The VST scanner is definitely broken.  I installed a new plug and the scanner will not pick it up.  I've run the scanner many times and it breaks every time. 

First, I'm sure you did this, but be sure you have the VST in one of the folders that the scan is told to search under VST configuration options.  I believe one time I actually copied one of the VSTs that Cakewalk didn't see (Lounge Lizard EP4 maybe?) from its default vst folder into the program files>cakewalk>vstplugins folder.  That worked.  Not sure it a good idea to have it in 2 places but it worked for me.
 
Second, here's a trick that worked for me when my VST scan would hang on an updated Autotune 8.1 version:
 
Right click on SONAR icon>Properties>Compatibility and put a check-mark in the box for "run this program in compatibility mode for Windows 8."  Then do the full manual rescan.   Some programs may complain (like AD2) as they think you are running the program on another computer which is not authorized.  I just temporarily uninstalled AD2 and reinstalled after the successful manual scan.  After that, I went back and unchecked the compatibility mode box and everything worked fine.  No further problems.
 
Good luck.

I have sometimes the same problem.
I can see that the scanner has scanned the plugin and shows it after the scan in the plugin manager.
But then it is not found in the "Insert Audio FX" Menu.
It it also not shown when I insert the plugin manually.
I have to restart SONAR, then it shows the plugin.