Well that didn't take long...lol. 
 
I've had X3b installed for 5 minutes and already it's crashing crazy and causing problems when I try to insert an instance of Waves H-Delay into a ProChannel FX Chain. I haven't had time to investigate this thoroughly, but here's what I've found so far:
 

• Sometimes inserting the VST2 version of this effect will crash X3b. Sometimes it'll crash first time, other times it will crash after I've inserted and deleted the effect a couple of times (I found this when trying to reproduce the problem). 
• The VST2 version is still not automatically configured as a tempo based effect. I had to go into the properties and do it manually. The VST3 versions are configured properly though. 
• Sometimes when I insert the VST3 version, the plugin GUI does not draw properly. It starts off with a blank white window and if I click around, various elements of the GUI make themselves visible. Here's what I mean:

 

 
I've been trying to reproduce these problems consistently for the last few minutes and of course now it's stopped happening. But my initial experience with these crashes and GUI problems don't leave me very confident about using Waves plugs overall, after having read elsewhere that Sonar/Waves compatibility problems had been fixed. I haven't had time to test all Waves plugins yet. Wasn't having this problem in X3a, or at least I'd never come across it. 

Ok, let us know if you are still seeing this issue. 

Did you reset all your plugins and rescan after upgrading? I'm pretty sure Noel mentioned something about updating the VST scanner.

Just did it. I didn't reset after installing X3a and didn't have the same problems however. We'll see....

Were you running sonar x3a and then closed it to install the update and then reopened without a reboot by chance?
 
If so is there a possibility that some of the plugs remained in memory cached by windows and when you opened x3b there was a problem accessing the cached plugs?
 
Noel?
 

Just tried to reproduce. I could not. The VST UI shows up as it should.

Are you intentionally trying to mix and match Waves VST2 and VST3 plugins? I mentioned it earlier on another thread that this scenario will not work. Waves has a limitation that you can only run the *same* types of plugins in a given SONAR session. i.e. if you insert a VST2 waves plugin followed by a VST3 waves plugin in the project, the UI for the new plugin will not draw and you will have instability.
 
This is why you should always keep the migrate VST2 to VST3 flag on. If you turn that off and load an old project, then you have VST2 plugins loaded, so any new Waves VST3 plugins added will cause problems.
As long as you stay with all VST2's and all VST3's in the same SONAR session you should be ok.
Important: Even if you load another document that contains a different VST plugin model type it is considered mixing and matching and can cause the GUI not to draw. I have reported this issue to Waves.
 
To troubleshoot this further, what is the exact scenario under which you encounter this? Are you just loading an X2 project in a clean session and encountering this issue when adding new VST3 plugins, even with the Migrate to vst3 setting enabled? If so that should not occur.
 
PS: an easy way to check whether its a VST2 or VST3 is by looking at the bypass button. If the button is grayed out its a vst2 and if its available its a vst3.
 
While talking with Waves recently we found one loophole. Under rare conditions when you open projects created on a different machine, it could cause the automatic migration to fail, leading to a mix of VST2 and VST3 waves plugins. Maybe this is what you are running into. Please investigate using the info above and report back. I addressed that corner case yesterday and it will be in the next update.     

Hi Noel, 
 
It wasn't really anything I was working on seriously...I'd literally just started a fresh session, loaded an instance of Lounge Lizard (to see what it sounded like), played a few bars and then tried to load an instance of H-Delay on the track. I think I started with the VST2 version, it crashed, so I tried it again and it crashed again. On subsequent tests of loaded, deleting and reloading the plug, it would crash after a few tries. It was at that point that I tried the VST3 version. Now to be honest I'm not sure if I had started a fresh session when I loaded the VST3...if I was forced to put money on it I'd say probably not, so maybe that's why the GUI glitch occurred. I have now enabled "migrate to VST3" and haven't seen any problems since (mind you I haven't worked on much in the last 24 hours) so fingers crossed and I will see how it goes from here. 
 
Thanks. 

Did you have hide Related VST2 plugins turned off? If you have it turned off there is the danger of adding a VST3 *and* VST2 plugin in the same session. With migrate Vst2 to VST3 turned off you have twice the danger since you can open a project with Waves VST2 plugins and then add a Waves VST3 pretty easily :)
 
If this is the scenario of your crash, there really is nothing more we can do from our side to address it since this issue is very specific to Waves. That's the main reason for the two options defaulting to ON which prevents this scenario under normal use. I suggest leaving both hide and migrate options on if you use Waves plugins a lot.
 
Anyway keep an eye on it and let me know if this problem recurs despite doing this because that would be an unknown scenario.

I didn't have Hide Related VST2 plugins on, put it that way! I think it is off by default. I definitely didn't have the VST2 and VST3 plugin coexisting in the same session - it was literally just one track and aside from the ProChannel EQ was the only effect I had in the project. I think I had them both in the same session (i.e. deleted one and then loaded the other) but never both at once.