yeah I've replicated this issue with 6.4, 6.52, and 7.4, with current UAD effects, and found issues only in X3 (64 and 32 bit), not in X2.  I can't say what UAD versions the other people who confirm it are using, but if it is related to the chaining API as indicated, I would think that there'd be no problems using whatever UAD version was current when Sonar versions 8-X1 were available.  I suppose the next step would be to try it using 32 bit Sonar X3 and pre-6.4 UAD.

CakeAlexS
Not sure what you mean by "recognition" but If you read Cakes statement the issue very clearly lies with UAD so you are probably on the wrong forums for that. Updates for your plugins will fix the issue and an X3E update may help workaround the issue, I wouldn't expect that for a couple of months. Not much more to say other than that really. I think the thread has served its purpose.

Noel's statement is that "this API is no longer actively supported by them at the host level... they would add a remedy from their end. From our side I have now removed custom UA chaining support from SONAR for the next X3 update...".  It sounds to me as though most of the UAD issues lie not with one or the other company, but are the result of a breakdown in their relationship, such that Cakewalk has continued to use a function which is no longer supported by UA.
 
As I've already written, my purpose in this thread is to speak with other users of both UAD software and Sonar X3, to try to understand what is causing these issues, and to develop workarounds or techniques to avoid problems with using UAD effects in Sonar X3.  Additionally, I hoped to apply a bit of pressure on Cakewalk to address this.  Noel has posted a helpful reply, in which however it's still unclear whether he is referring only to the "-21" error, or to the broader spectrum of issues which have come up.
 
I hope to continue receiving more replies from UAD users, ideally with a view toward understanding whether there is a key difference in systems which accounts for why Danny reports no issues when following the recipe I posted, which in my and some other systems creates an error consistently.  I have also been on the UAD forum, asking people there to attempt to replicate the issue as well.

brian brock
I would think that there'd be no problems using whatever UAD version was current when Sonar versions 8-X1 were available.

Maybe but then..
 

Noel Borthwick [Cakewalk]
is because the UAD driver seems to be testing for a specific SONAR version...

The current UAD driver tests for versions of Sonar and makes some changes for them, specifically repressing the "-21" error popup.  There may be other changes as well.
 
Older UAD drivers, which were written during the period of greater cooperation between Cakewalk and UA, apparently implement a "custom chaining API" which at that time was still "supported by them at the host level".  So, if Cakewalk's Sonar X3 code still expects this custom chaining API to be supported at the host level, it is reasonable that Sonar X3 will work without issues with the older UAD version.
 
I could be wrong.  I don't understand any of this, I just want to get some of the best effects plugins to work with Sonar X3

I can report that UAD version 5.5 does not show any of the issues I am aware of in Sonar X3, either 32 bit or 64 (in which the UAD 5.5 32 bit vsts are bridged).
 
Since 6.4 does not behave, and since 6.31 was the version which introduced the mysterious "(Logic Pro) UAD plug-in chaining reduces latency" feature update, I am going to guess that 6.3 is the latest UAD version which will work without problems in Sonar X3.  Assuming the user doesn't need to use 64 bit UAD effects (32 bit UAD may still work fine in Sonar X3 64, for all I know), nor needs to use UAD fx released after the Lexicon 224 and 1176 mkII, it might be worthwhile looking into staying with 6.3 for the time being.

I guess I m very lucky!   My FX toggle works everytime and I use UAD plugs as my main FX source both as insert, loop AND FX CHAINS mixed in with non-UAD.  Everything works great and when it doesn't, I toggle FX (disable all FX) and press again (enable) and it's all good!    Good luck and I hope this get fixed properly down the road.  

here is my summary of what I found after looking into this thread's UAD problems:
http://forum.cakewalk.com...happened-m2964885.aspx

 Same here as Stxx, toggle global FX gets the PC fx bin UAD plugs working here.
 None of the UAD issues mentioned here that I've seen have been exclusive to X3 here, when X2 was first launched the exact same issues with noticeable loss in UAD performance and the"-21" error were all present here in X2 until UAD fixed it with a new driver.
 IMO UAD drivers have been hit and miss, mostly miss, since they went 64 bit exclusive. I have both XP 32 bit and Win 7 64 on this machine and the older UAD plugs perform much better in X2 on my XP 32 bit install than they do on the same project opened up in Win 7 64. With their 64 bit version
 It just doesn't add up to me, how plugins designed to utilize processing and ram power from a card could in any way benefit from being 64 bit?
 I also highly doubt they have done anything to the code of the older plugs, that were designed from the ground up to be DSP powered. I'm pretty convinced there's some kind of internal UAD wrapper.
 TC powercore stopped development years ago, but they are still updating their drivers and work without issue here in projects loaded with other 32bit wrapped and 64 bit plugs. VST 2 and VST 3.
 
 
 In any case, folks are free to direct their blamestorming at who they choose. UAD does not officially support Sonar. I read they plan to drop support for their PCIe cards in the mac platform. They dropped support for UAD-1 ... A pattern?
 
UAD working here in a slightly crippled state in 64 bit. I'm done buying UAD plugs until they take more responsibility for what they sell.