Here were my steps:
 
1.  Selected bars 14 - 15
2.  Edit > Copy
3.  Selected bars 16 - 17
4.  Process > Groove Quantize
5.  Selected "Clipboard" for the source, left everything else at default, hit OK
 
No changes made.
 

Sorry, works for me every time so I have no idea what to recommend. What version of SONAR are you running?

Anderton
Sorry, works for me every time so I have no idea what to recommend. What version of SONAR are you running?

2017.09
 
I am noticing it works for simple patterns, but if you get even just a little complicated like my original image, it doesn't work.   
 
I will experiment more to try and come up with something.  I might open a support ticket and upload my file, but first I am going to experiment more, see if I can find out what exactly causes this thing to not work.

If you can come up with a recipe to reproduce, post it here. I simply can't get it to misbehave. As to complex patterns, you may need something other than the defaults.

I'm having the same issue and have had it for a couple versions. I actually just came to the forum to see if anyone else was having the issue and if there's a resolution yet. I have the issue on Windows 7 and Windows 10 and on multiple different PC's with different configurations.
 
Sometimes rebooting makes Groove Quantize (GQ) see what's copied to the clip board correctly. Sometimes GQ deletes all the notes I try to GQ. I've noticed that the first note usually has to be perfectly quantized to the selected resolution for GQ to work.
 
I'm trying to switch to Reaper but been using Cakewalk Pro Audio and Sonar since 1997, so I can work faster with it but lately I think it would take less time to learn something new in Reaper than to use Sonar just to find out something doesn't work correctly anymore.
 
The Audio and MIDI interfaces I use: 
* Focusrite Scarlett 6i6 1st gen
* Fractal Audio Systems Axe-Fx II Mk I and XL+
* Line 6 POD Studio UX2

GotMetalBoy
I'm having the same issue and have had it for a couple versions. I actually just came to the forum to see if anyone else was having the issue and if there's a resolution yet. I have the issue on Windows 7 and Windows 10 and on multiple different PC's with different configurations.
 
Sometimes rebooting makes Groove Quantize (GQ) see what's copied to the clip board correctly. Sometimes GQ deletes all the notes I try to GQ. I've noticed that the first note usually has to be perfectly quantized to the selected resolution for GQ to work.

I can confirm:  a reboot resolved this issue for the time being!  I am using the same pattern and the same project and after a reboot, it worked!
 
Something is up here.   
 

That's useful information. If what you think is being copied to the clipboard isn't being copied, that would produce the results Adam and you have experienced. I'll try to figure out why SONAR is seeing my clipboard, and maybe that will solve the issue.

Anderton
That's useful information. If what you think is being copied to the clipboard isn't being copied, that would produce the results Adam and you have experienced. I'll try to figure out why SONAR is seeing my clipboard, and maybe that will solve the issue.

Hi Anderton,

The clipboard IS being copied because before I was able to copy/paste the notes in the PRV.  I think the problem was the Groove Quantize feature sometimes can't read the clipboard - until a reboot.
 
I will try some more over the coming days and report back.
 
Thank You

I just found a post I created 1 year and 1 month ago for the same thing I'm trying to do right now.
* http://forum.cakewalk.com/FindPost/3479658
 
I was just going through my Evernotes to see if I have anything more about this issue and it looks like there are 2 things that sometimes seem to affect it.
 
1. In the initialization file TTSSEQ.INI, there's a Variable in the [Options] section: MfxLookAhead=3840
** Defines how much extra MIDI data is sent to MFX plug-ins, so that they have extra room to quantize events into the future
** Lower values mean MFX plug-ins can work more "just in time"
** Example: MfxLookAhead=480
** The default is 960*4=3840 ticks
 
NOTE: Also, I recently changed IgnoreMidiInTimeStamps=0 to 1, so not sure if this is causing any issues.
 
2. In Preferences > MIDI > Playback and Recording > Playback > Prepare Using: 500 Millisecond Buffers
** Prepare Using N Millisecond Buffers
** This option lets you specify how far in advance SONAR prepares MIDI data during playback
** The default is 250 milliseconds.