To try and keep a better understanding of this issue, I've edited this post: 


I'm finishing a CD project with a deadline and I am trying to solve a problem.
I have been using NI Komplete since the inception of this fantastic product and have been a Cakewalk User since Cakewalk 7 Pro Audio. Today I ran into some issues with Studio Drummer In Kontakt 5 not playing some midi groove loops that fully in a project. 


Tools and software: [Cakewalk's Sonar X1 D Producer Expanded, with Komplete Ultimate. Sonar X1D Producer Expanded; Win7; AMD Phenom (tm) 9750 Quad Core Processor 2.40Ghz; 8Gb Ram; Motu 828Mk3 interface; Edirol PCR500; M-Audio Trigger Finger; Frontier Transport] 


Project: 20 tracks with 4 VST instruments, Trillian, Kontakt with Studio Drummer, Dimensions Pro, and Kontakt with Broadway Horns, the rest of the tracks were recorded audio. 


Allow to me to explain how I create my projects. After I've written a song or project, I will often start sketching out the structure of the tune by creating Groove Loops within SonarX1 per section (intro, verse, chorus, bridge etc). I save them within the project folder in case I need to recreate the project on the fly. The work is done and easy to replicate. 


While editing this project, I was working on my Broadway Horns tracks within Kontakt 5, and all my other VSTs tracks were in "Freeze" mode to free up memory. I've been doing this for quite some time without any issues. Works tremendously. 


When I finished with that track I had a "Not Responding" message with my SonarX1 and it went into "Ghost" mode and unresponsive. I quit the program and rebooted as I do when such things occur. 


When I re-opened the project everything was playing fine. I then went to work on my Studio Drums track. I "Un-Froze" the track and was missing the Studio Drummer within Kontakt. I reloaded Studio Drummer and found that certain groove loops were not playing fully. ie. The Bridge clips were missing the high hat hits and the Chorus clips were not playing the kick and snare hits. The midi notes were there. The velocities were there. The Snare, Kick and Hi-hats played via all my midi controllers. 


I thought it might be the project. I then closed out the project and opened a new project, with one vst: loaded Studio Drummer, same drum set, and tried the groove loops in question. Same problem. I tried groove loops that I've created over the whole past year, and every loop played flawlessly. I tried different drums, all the Abby Roads sets, with the loops in question. Same problem. Missing hits. 


I then re-installed Kontakt and found an update for Studio Drummer, which I installed. Rebooted, and the problem isn't resolved. 


I tried another option. I "converted midi clip to step recorder" and all the parts played, however, I lost the feel that I originally created. I spent a lot of time on replicating a live drummers feel for this track. 


I am completely loss for a solution. And I'm reaching out to both software companies for help, Forums and Tech Support Email. I've spent hours on the drum parts and re-creating them would set me back on a weeks worth of time, and I've got to finish my CD project on time. 


Thank you.

Oh.  I also tried bouncing all the groove clips to one clip.  No a fix.

Amazing!  I had the exact same thing happen to me early this morning while working on a project -- I come here and your post is the first one I see ... lol.  I was afraid that my problem might have had something to do with me defragging my DAW the other day, but unless you did that too then the problem is elsewhere.  I don't have an answer, but like you I'm anxiously awaiting one.

Velocities where they need to be on the notes that are sounding out?

I don't do much midi but isn't there a way to mute specific notes in the PRV?  Could that have happened?

Double Grrr.  

Somehow the groove clip is affected.  I don't know how.  I just ran this test. 

Opened up a new project.  Opened up the Studio Drummer VST and dropped in the section groove clips that are not playing properly in the problem project, and they are behaving the same way.  

When I open up the groove loops within the piano roll all the velocities are in tact.  I can play the parts that are missing on my midi keyboard controller and other controllers and within the piano roll on the side virtual piano.  However, when I click on the parts in question they do not play.  Yet the other parts do play when I click on them.  

P.S.  I think I said that this was Session Drummer in the original post.  That is incorrect.  I'm using Native Instrument's Studio Drummer in Kontakt 5.

I know these moments can be quite frustrating Terry.  You'll be in the loop when a solution arrives. 

Mod Bod, are you referring to the PRV as the Piano Roll View? My last reply explains my work in the PRV.

This may seem an odd question, but are you using Perfect Space Reverb and LP64 EQ on any tracks?

jb101.  There are no odd questions when working a problem.  :) 

I am not using either of those plugins.  On any tracks.  

I may have muted the notes in question on the clips by accident.  I'm trying to decipher that now.  I do use some quick keyboard shortcuts in my editing and I have made some mistakes with some sloppy keyboard shortcut mishaps.  

Just tested the groove clips in Session Drummer and they work fine.  So, I don't think it's the clips themselves.  Something in relation to the Studio Drummer or Kontakt.  Going to try another drum set in Kontakt.

Have you checked your MIDI buffer settings? Preferences-->MIDI-->Playback & Recording--->Playback.

The default is 250 msecs although IIRC CW recommend 500.....