Rapture Pro & Session Update 4 Now Available! 
http://forum.cakewalk.com/Rapture-Pro-Session-Update-4-Now-Available-m3359235.aspx#3359235
 
Cheers!

I heard back from Tech Support and the update is suppose to fix the issue I was having. (I applied the update and everything still works.) Tech Support said if it didn't work to open the Mixer Menu and then click on Mod Matrix. Then find cc 127 in the source list and set it to off. I checked it out and cc 127 doesn't appear to be listed anymore.

i guess they will have to rewrite the manual then. :-)
 
Modulation Matrix Sources
Source Description
CC 1 – CC 127 MIDI Continuous Controllers 1 – 127

CC 127 enables polyphonic mode, which disables monophonic operation, so it's not really pertinent to Rapture Pro. Perhaps the issue came about because a CC127 message should automatically turn off all notes that are sounding. Maybe a controller sent out a CC127 message to insure polyphonic operation, but after receiving it, RP got stuck in a "no notes sounding" mode. If the last update took out the option to receive CC127 issues, it's certainly no loss.

Some existing instruments/presets in rapture pro use CC127 in the modulation matrix as a source for a modulation destination. Did cakewalk go through and reassign these to another controller when they removed CC127 from use? Or did that existing mapping just disappear from existing instruments/presets?

Tech Support never said that it was removed so I don't know if it was or it wasn't. He just told me if I don't get any sound to goto the Mixer Menu and then open Mod Matrix and turn CC 127 to off in the source list. I wasn't getting any sound and when he turned that off, I got sound again. He also said the the new update that came out after we talked fixes the issue.
 
I said that I don't see it in the list when I open the Mod Matrix. Maybe I haven't opened the right instrument or maybe I haven't done what ever triggers it. Or maybe it was removed. Maybe that's why I don't see it. Most of this is all new to me so I don't even know what it means.
 
I did try several different instruments and I don't see it listed in the Mod Matrix.
 
Anyway, I'm happy that my issue has been fixed.
 
And I also meant to thank Atsuko for telling me about the update.

Kev914
 
(...) And I also meant to thank Atsuko for telling me about the update.

You're wellcome!!

okay, thanks for the response looks like they have not removed it. it is still available for source selection.

Can someone please confirm that this is properly fixed. I get exactly the same symptoms as the OP ( No sound through Rapture Pro, despite the routings all appearing to be OK, and by switching to another synth such as Dimension Pro it works fine ). I have Manchester build 21.12.00.36 and Rapture Pro update 4  build 2.0.4.25 installed. If there is a work around or a check on CC127 that I could make this would also be useful information for me. Thanks