If anyone can enlighten me, it would be appreciated  
 
I have another recurring annoying midi issue, (aside from recent Melodyne midi file issue), eventually in some projects, at some point in history, I seem to get certain or random midi notes in a soft synth track that don't "sound" during a continuous playback, although they had initially sounded properly, if I stop playback, and play from start of that measure, note may or may not be heard, when it does happen noticeably it usually affects full track,  occurring on at least one seemingly random note count, or possibly same pitch or time count in various or all measures throughout track, file editing functions play note when selected, midi popup menu shows note properties appear OK, velocity is good, same note pitches aren't overlapping, deleting and reinserting a new note may or may not fix, in some cases this shifts issue to an adjacent note. This may or may not be happen in all project soft synth tracks, or may at different time counts, sections or measures, so not necessarily related in time, i.e., different tracks don't necessarily  lose note at same time count. However, when I bounce the synth track to an audio track, the notes are all there, and usually how I have dealt with issue, albeit I'm then stuck with that bounced audio arrangement, or have to go back to midi to edit and/or redo.
 
Is this a known inherent "thing" with midi, and/or digital processing or sampling issue where bits of data are somehow being lost after generations of a files evolution, and an issue to be expected (as I've come to think) or is there a known specific reason that this occurs, and that can be prevented or cured?
 
signed
Midi Challenged          

A classic one, this.
 
Edit>Preferences/MIDI/Playback and Recording
 
Now, I've forgotton, is it Number of Buffers or Prepare using xxx Millisecond Buffers?
I think it's the second one. It needs to be increased. On mine it's 500.
 
However, this issue is old and the default was increased quite some time ago.
Perhaps it's dependent on the platform.
 
Try values around 500-1000.

Thanks for feedback,
 
I have had it set to 500, Ill try going to 1000, and see what results I get, I had thought going to 1 second would be  somewhat excessive and possibly cause other issues (and relatively like a long time, LOL.), albeit I usually run RME-UFX at high or highest latency setting for playback/editing, Which would lead to a question,
 
Is their any reason not to run an audio interface at the highest latency, for playback/editing?
 
I determined a problem/solution (for this project at least)  
 
I had spent some time to late last night doing some sleuthing (which I detest) track by track, with a such troubled project, only 3 soft synth tracks (all dropping random notes) and 20 analog tracks, and found on "1" of 10 audio vocal tracks,
 
IZOTOPE Breath control running in ProChannel FX-Chain module, as it turns out this was the culprit, and like a switch, "on" midi notes are dropped, "remove" all midi notes are all OK, and perfectly repeatable. This led me to recall issues in the past whenever using IZOTOPE Nectar plugin in an FX bin, they really seem to excessively hog processing time to the max. Normally now when using their plugins, I set them up on a track as desired, create a pre-set and then run as a process fx on track or clip, and then get rid of them, as far as possible, (perhaps to even store them on a different computer, behind a glass enclosure with a hammer, with nuclear symbol labeled  "use only in case of extreme emergencies", LOL, but they do their job well if given their space). Ill try it though bumping up midi playback buffer time, and see if it works in "real time", without affecting midi synths.
 
Also the IZOTOPE Nectar fx have a number of option settings for sync, buffer and delay compensation which I'm not sure I fully understand yet, but do refer specifically to Sonar compatibility settings, dam more homework to do, :(.
 
Cheers
 
   

To me, low latency is important when I play a keyboard triggering a VSTi synth. It is the time between hitting the key and the sound starting that puts me off. Piano and drums are particularly disconcerting if there's a significant delay.
 
But most other delays are compensated for automatically inside Sonar. The only thing is Sonar takes a while longer to start playing.
 
500 is kinda normal. 1000 is indeed high. But I usually only use a drum and a bass plug, so maybe you need to put yours up. It's always been a bit of a mystery how much is enough and when...
 
I also find iZotope Oxygene process-heavy.
Is freezing tracks an option for you?
 
 

Thanks for reply,
 
Definitely while recording my latency is always set low, and maxed for playback, my music is guitar orientated and not overly complex, initially usually limited to basic midi drum loop as a click, and basic rhythm and/or bass, tracks and build that up from there later, with synth or other, I don't typically have any latency/delay issues in my recording process. I could definitely freeze, but not too familiar with its use, typically I would bounce audio instruments to track or clip when happy with their sound processing and/or other editing, and go back to earlier versions if ever requiring the dry track/clip, just to keep working file relatively smaller, but typically would retain midi synths as midi, to final export. I do usually retain dry unprocessed vocal tracks in current working file, and last thing I try to get right. At some point I forgot I had the IZOTOPE breath control processing left on dry vocal track, and which apparently has a significant effect on midi based tracks.
 
Cheers
John Egan