Notes don't show up in Piano Roll

Are you looking in the right place? Keep in mind that the PRV is many octave and can be very long. Zoom out and maybe that will help. Also be sure you have the right track in it.

Thanks for trying, I give up for now, Sonar defeated me today, one day to work on stuff and couldn't do it. I appreciate the effort, but it may be time to look for another program, seems like every other time I try to work I have to track down some ridiculous little issue before I can do any actual recording or mixing. If you have any other thoughts, I may look into until I can find something else.

can't say i have ever come across it myself in the past, so i just gave it a whirl, loaded a drum vst and just tapped out a beat with my midi keyboard, recorded it, open prv and everything was there, do you see the notes you played represented in a midi clip in track view?

I would suggest bouncing all of the MIDI clips to a single clip and then look in the PRV

right click on your midi track and choose View> Piano roll view.
sounds like a classic case of wrong view in prv.
 

The Step Sequencer option is greyed out, maybe that's a clue, but I don't know what it means.
 

I do see input represented in Track view, though it looks different than what I'm used to. It's a continuous purple line that gets thicker where notes are played, instead of the dashes I'm accustomed to. This a SD3 folder I'm working in.
 

That's how I always get to PRV, and the PRV is labeled correctly to the track I'm working with.
 

Give a step by step on how you are doing this. Start from the very beginning. For example I record enable track 10 then....

You guys might be right, I was opening the PRV right clicking on the specific instrument, in this case Percussion 2 in Session Drummer 3, instead of the SD3 midi row at the top... the notes show up there. Although, this still seems strange to me, I've done this quite a bit and I'm used to having the keyboard representation to the left instead of just the instrument list. Maybe I'm misremembering.

Always use the track that has the MIDI data in it.  

Off topic, and I'll do it as a separate question if that's more proper... but I'm curious, in SD3, when I create a SD3 session, it offers me a list of labeled tracks from Kick all the way down to Percussion 2, 3 & 4, but no Percussion 1. When I open the kit, there is a trigger pad with four pads for percussion, and in the mixer all four pads are represented, but when I load a percussion instrument to Pad 1, since there is no Percussion 1 in the track view, it shows up on the track labeled Splash Cym. Is this by design, or something glitchy? And is it possible to add a midi-audio track to an DS3 session to make up for the missing Perc 1 without losing the Splash?

I never/rarely see notes in PRV until I move the little slider at the bottom of the window.  Weird, but I just live with it now that I "get it".

GregGraves
I never/rarely see notes in PRV until I move the little slider at the bottom of the window.  Weird, but I just live with it now that I "get it".

Yeah - I see this a lot too. This bug has been around a while but only shows up when using a keyboard shortcut (and maybe the dropdown menu?) to open a new docked PRV window. The velocity bars appear,  but notes are actually placed fowarding on the timeline until the window slider is moved, then they allign correctly . If you leave a docked PRV window open and just allow it to refresh, or use double click to open the PRV it should not happen. It also does not occur in an undocked PRV window no matter how it is opened.