I can freeze a synth in old Sonar 1 & Sonar 2. But Synths will not freeze in Sonar 3 or Sonar Platinum. The freeze function runs through but I am left with only 2 (stereo) flat lines in the audio track. I've checked my settings and all seem to be good. Can any one help with this problem? (again but works fine in the older versions.

Which synth(s)?

East West Symphony Gold using their "Play" engine

Doesn't address your problem but since I got splat I never freeze anymore.
It takes way too long compared to a real time recording.

It might be easier and faster to record them all at once in realtime.
There are record "ARM" buttons now on the synth tracks.

I figured out that if I deselect "fast bounce" in the freeze option it renders the audio file- if not I get the same results. Hope that fixes your issue as it did mine with my version of EW.

Thanks I have tried real time bounce also. Seems odd that it works in sonar 1 & 2 and not in sonar 3 & platinum. I always say if it aint broke dont fix it. The millennium is the era of the "new improved worsers" Since people are out of work if everything works, you have to break it to make it feel different, then improve it again conspiracy. 
 
Well if anyone else has any input, id appreciate the input.  Thanks

I'm betting it's something specific to the EW Synth.  Can you freeze other synths (try one of the CW-ones, like the SI instruments)?
At the very least, that will identify whether it's Synth- or DAW-related.
It's more work, but what happens if you Bounce To Track?

Hi. I have not had any issues freezing EW Play in the latest (EAR 05.2017) SPlat.
Do you have the latest version of Play?
All the best.