CWBRN-1824, Drums Map prevents Midi Input
SUBMITTED TO DEVELOPMENT. With the following notes: Thank-you for your report. We are aware of this and hope to address it.

Ok, so I got 8.5 and this was the first thing I tried, and sure enough I can repro it.

However, something that I thought was REALLY going to be a problem was really just an inconvenience.  I was expecting that the arpegiator, when enabled, was suddenly going to start affecting the vdrums brain with a bunch of notes.  But this didn't happen and everything else seemed to work normally.

Obviously this is still a bug that needs to be addressed, but it didn't seem to cause any real issues for me except that it needed to be enabled on the midi track...but unless I select a pattern, no additional midi seems to be getting introduced to my stream and therefore is working ok, even for the live through, recording, and playback.  This is all using an external midi module, not a VSTi - havenm't had a chance to try anything else but this so far and I was glad to see that it was only going to be an issue of remembering that I need to enable the arp (which I have now saved in my template for the vdrums midi track) until they patch this.

Am I missing something about the severity of this problem?

Really, no settings - I've just clicked the arp "on" button, no preset selected.  I didn't notice any additional latency, but remember that I'm using this to an external midi device (Roland TD-20) not a VSTi, so I may feel something different when I test with that.  I've also only tested from my keyboard controller, not the vdrums themselves, so maybe I'd see something with faster or more complex drum figures.

Thankfully, it's fairly rare that I play realtime through a Drum Map anyway.  When I record my vdrums, because it feels better to me this way, I have local control on at the brain and the midi cable FROM the pc TO the td-20 gets disconnected for tracking and reconnected for playback.  This way, I'm just monitoring what comes from the vdrums, rather than what it going into and back from Sonar to the brain, so latency is minimized as much as it can be.  Even if I am going to replace some drums after-the-fact, I don't monitor with the VSTi versions anyway.  This is obviously just my workflow, but it works for my situation.

Mike,

So, I've now managed to break the arp the rest of the way and can't get it back the way I had it.

It appears that the bug as you described existed for me, except the arp wasn't actually affecting midi input.  It was just that I had to enable the arp to get midi to go through.

Well, now if the arp is not enabled, I get no sound, AND when the arp IS enabled, I get sound, but it is unfortunately arp'ing the drums.  So what made the change?  I tried playing with the arp on another synth just to see how/if it worked - sure enough it did and I can think of lots of uses...so I go to enable my drum track to record so I can lay down some stuff around this arp'd synth and the drums start arp'ing.

So, it seems that by enabling and loading a preset in the arp at all made the arp'ing begin to happen on the drum-map channel, not to be turned off again - at least not so far as I've found a way.

I looked around the system and can't find a file that changed and I don't see anything readily apparent in the Registry.  Choosing "none" for a pattern also does not help, as it just continues along doing some "simple" pattern (i.e. a change happens when selecting NONE, but it's not "none").

So here's a workaround that worked for me so I can use my map with the arp ON and it doesn't arp my data: 

Show the arp setting details (right pointing arrow next to the worp apeggiator) in the track view widget.
Select the parameter "mix %" and set it to 100%.

This makes the source be at 100% and the arp be at 0%.  So I guess it's still going on back there, but you can't hear it and it has no apparent affect.

Does that work for you, Mike?

FWIW email today saying
CWBRN-1824
Thank you for your report. This issue has been fixed and will be available in the next SONAR update. You can access the latest SONAR updates and knowledge base articles at http://www.cakewalk.com/Support/SONAR/default.aspx

So it sounds like it's made it through testing.