Can somebody check this?
I'm running the latest Splat 05-2017, I went to transpose an acoustic guitar up a step from G to A using the good old Process, Transpose, [ ] Transpose Audio. 
No matter what algorithm I try, the resulting section transposed is either choppy, choppy white noise or in the case of MPEX Polyphonic - flat line nothin.
 
I haven't tried this since way back in 8.5 when it worked.
 
I only have Melodyne essential so I have to use Sonar's (which wasn't bad)

I tried it out on my laptop just now and it works as it should so, crap, there is something wrong with my DAW in this respect.
My DAW is windows 10, my laptop Windows 7

I just tried it on a few tracks and it was fine, I didn't see the MPEX Polyphonic option that you mention. I selected the Radius Mix option, and was able to transpose a bass and guitar track up a tone with no audible artifacts. My system is Win10 and I'm on the 05 update.

Hey! thanks for trying it.
 
I'll try other projects and things tonight and see it I can't corner the issue.
 

millzy
 I didn't see the MPEX Polyphonic option that you mention.

MPEX is 32bit only. It does not appear as an option in 64bit SONAR.