That is a bit strange because the VST3 plugins featured in RX10 Elements are also VST3 plugins in RX10 Advanced and those same VST3 plugins do work in Vegas Pro 21. Maybe there's some coding difference with these plugins if sourced from RX10 Elements or Advanced.

This seems to be similar to the problem of Melodyne 5 VST3.
dimitar explained that this is because Vegas 21 does not support the ARA plug-in of VST3.

I posted the identical problem a week or two ago. Upgraded from RX7 to RX10 and while the RX7 VST3s still show in Vegas21, the RX10 ones do not.

I confirmed they are in the same VST3 directory. Not only that, but when rescanning for plug-ins, I can literally see the RX10 plug-in names display -- they just never show up in V21 as plug-ins for me.

The support folks gave me the same response -- "Vegas isn't an officially supported host, and we haven't and won't be testing it. It's probably a problem with Vegas".

Although they have a no-refund policy, the folks who sell the Izotope products were kind enough to cancel my license and refund my purchase. I just don't have time right now to troubleshoot, but do hope one day to re-purchase and hopefully get it working since I'd like to benefit from the new versions of their tools. I realize I could do the round-trip approach to process clip audio files in the external RX10 interface, but it's not my preferred workflow at the moment.

I wonder what changed since RX9 which does work.

@Billy @RedRob-CandlelightProdctns @Dexcon @Elynde @lan-mLMC 

I have RX10 advanced, I do not have an issue with RX10 and Vegas 21, they show up (apart from those which are not available as plugin like wind reduction) and can be used in Vegas 21, even the RX9 (which I did not uninstall) shows up.

Maybe because I still have RX9 not uninstalled yet, that RX10 shows up?

@bitman  ... RX9 Adv is not installed on my system - only RX10 Adv, I don't think it would be an RX9 "ghost" in the registry because late last year I upgraded the M.2 SSD C drive to a 2TB M.2 SSD and re-installed Windows 11, so only RX10 Adv has even been installed on the current C drive Windows 11 installation.

It's curious as to why basic RXVST3 plugins work well in Vegas Pro 21 when those plugins come from RX10 Adv but not from RX10 Elements. I wonder if the plugins from earlier versions of Elements that worked in Vegas Pro were VST2 plugins rather than VST3 plugins. I think that RX10 is the first RX version that no longer has VST2 plugins so it might be that its the Elements VST3 plugins that are not compatible with Vegas Pro.

I was trying to get RX10 basic (not advanced or elements) to show with no success.

I did have RX7 installed at the same time and its VST3 did show up OK, just not RX10 VSTs.

So "Advanced" shows but Basic and Elements do not?

The RX10 Elements & RX8 Elements VST3 plugins show up and work in both Vegas 20 (build 411) and Vegas 21 (build 208, trial version) for me.

RX6, RX9, and RX10 (advanced) show up for me inV221 B208.

This might be a silly question -- but why are *we* debugging the problem?
I mean -- it looks like it works for some people, and not others.

Shouldn't the folks at Izotope and Magix (Vegas Creative) have an interest in figuring out the root cause and getting it fixed?

Izotope doesn't really have an incentive to figure it out unless they think it is an issue for many users. Afterall they never promised compatibility.

VCS isn't so well resourced so to the extent we can figure out the scope of the problem (who it affects) the more likely they can replicate and solve it.

Hi everyone and thank you for reporting those RX 10 problems. We have been looking into this issue and we will try to get to the bottom of this. We are actively trying to figure out what is going on there and resolve any issues on our side as soon as possible. There seems to be something rather strange with RX 10, which we struggle to reproduce consistently, since with a clean installation of RX 10 (and VST rescan if needed), the plugins are found and work in VEGAS in all our tests so far. Izotope do provide a number of other supporting dlls, which, I believe, can get in a rather messy state - if one has multiple versions of the plugin, or some update do not run cleanly, so that the version of those dlls do not match the VST3 somehow. This is so far the only way we have been able to reproduce the issue and sadly, there is not much on our side to be done about this. But, we will continue looking into the issue and try to resolve it. Thank you

I always think of VST plugin usage as very simple - scan folder for 64 bit dll and done. Can you define I clean installation of RX-10? Do you mean a fresh install of Windows that hasn't ever had an iZotope product installed on it?

I can confirm that in VP21, build 208, RX10 Advanced VST3 plugins do not show up, even after a re-scan. I thought it might be a folder issue, but the iZotope Ozone 11 VST3 plugins are in the same exact folder, and work with no problem. I can use a workaround, like pass RX10 through the Blue Cat Axiom VST, but I would really want to avoid that...

UPDATE: It seems that in the latest VP21 build, it works.

Everything was working in Vegas 20 until I added another plugin folder which knocked out all RX10 plugins for some reason. Tried everything-uninstall/reinstall RX and Vegas, with reboots in between, registry checks, etc. etc. , nothing worked. Finally, I installed the trial of Vegas 21- it put the plugins back on first load. I exited the trial, ran Vegas 20, and they were back. Hope this saves someone else from losing 10+ hours like I did today.