This goes for ALL softsynths (just different parameters), I am choosing Z3TA+2 at the moment to keep it all Sonar, but basically, you dial in a sound (or open a .fxp preset), save the file, and the re-open the project, and your synths have changed!

Steps:
 
1.  New Project
2.  Insert Z3TA+2
3.  Open a preset (the one i used is here:  https://www.dropbox.com/s/pmp0eyip9qh7u2j/patch.fxp?dl=0)
4.  Save the project file
5.  Re-open the project file, parameters have changed.

See the video below, and watch the AMP-Release magically change!

https://youtu.be/ovunWzz20B0


here is a closeup from the video:
Here is the patch after saving:


 
and after reopening:
 

I have tried this and am unable to replicate sorry.

yeah i had a quick go and also could not repro, sorry!

Hi. I was not able to replicate either. This on my laptop.
All the best.

Just tried to replicate it and unfreezes just fine, can't replicate.
 

are you running the latest version of zeta? (i had to go through all the BMP vs PNG mess before testing because i hadn't updated for a while)

yes i am running the latest version.
 
this happens on ALL softsynths, so it's not just Z3TA.

Wonderful, I guess this is something I just have to live with.  :(

is it a simple instrument track or a midi/audio pair? in a folder? with midi out enabled? etc