Here: https://www.waves.com/sup...-after-updating-to-v10

How did you find this? Interesting. Must be some major problems with some systems.

There’s an entire misery thread on this with a guy from Waves chiming in: https://www.gearslutz.com...-now-available-13.html

Oh, ok. I'll check that out.

So when I upgraded to V10, I left all my V9 plugins on my system and didn't uninstall them.  Which meant I had two copies of just about everything that got a V10 upgrade.  Oddly enough this didn't seem to be a problem.  Some hosts actually only showed one copy (SONAR/Bandlab and Cubase) but others like Reaper would show both, but they would both be usable.
 
Since Wave keeps saying you shouldn't have both V9 and V10 installed of any plugin I ran this utility.  It seems to move the Wave plugins that are normally stored in c:\Program Files (x86)\Waves\Plug-Ins V9 and Plug-Ins V10 that you don't have licenses for to two new directories, Unused Plug-Ins V9 and Unused Plug-Ins V10.  Just be sure to run it as admin.
 
Sadly this didn't fix Reaper from showing two copies.  Only now the second copy wouldn't work.  Had to do a full clear cache/re-scan, which was very painful.  Between the iZotope plugins hanging because I use iLok authorization on them (a long running issue with their plugins) and the 10 minute+ timeouts that the Native Instruments plugins all take (due to the fact I've had/installed every version of NI plugins since the early 90's so my registry entry list is so huge they take forever to scan/load) it took a long while to get REAPER back.  But once I finally got it through the scan (only a few crashes and a handful of restarts) my Waves plugins are now only listed once.
 
One of the threads on Gearsultz a Waves rep confirmed that once you get a V10 license all the V10 updates will be included even if your WUP expires.  Just like it worked with V9.  If they ever update any of the V10 plugins I have I'll be able to see for sure if that works, since my WUP has expired on a bunch of my V10 plugins recently.
 
With this utility I think the best upgrade for a mixed V9 and V10 world is.  Update your licenses (on Waves website), install the new Waves Central, Install all the V10 plugins you have licenses for, don't take any of the V9 uninstall options during that process, then run this tool.

Fleer
There’s an entire misery thread on this with a guy from Waves chiming in: https://www.gearslutz.com...-now-available-13.html

Well, reading that GL thread confirms definitly my decision to stop using Waves plugins (have only a few) and never ever buy some! Waves is an ill-natured, furtive company that preys their customers. Please get me right, I don't want to discuss about plugin quality! It's just their way to catch customers like me with plugin deals and then they try to take you hostage with so-called upgrades, disregarding their ugly installer, limited 2 computer support, slow scanning shell (yes, my scans run now obviously faster). So in the end I feel that I just had thrown away my money for nothing.
 
Marc

I have just updated all of my Waves plugins using Waves Central. Some are V10 (with or without WUP) and some V9 (with or without WUP).
 
I followed the instructions as per Waves Support -> Manage Products https://www.waves.com/support/update-to-latest-version and all seems OK.
 
That is:
 
- Ensure all owned products are activated.
- Run Waves Central and do the updates. (This installs V10 versions of V9 products I own)
- At the end of Waves Central updates Do NOT uninstall V9 products. (Keeps the V9 products I own)
- Download and "Run as Administrator" the V9-V10 Organizer.
 
Now the question is, moving forward whenever there is an update will I have to do all of the above every time until such time as I have paid for upgrades to V10 of my V9 products? Seems like a PITA to have to do this for every update.

I don't believe they will or can update V9 plugins anymore.  They are now "dead" as far as updates are concerned.  Only V10 plugins will get updates and Wave Central will do the updating of them.  So you shouldn't ever have to do this crazy dance on that machine again.
 
If you are setting up a new machine, I believe you will need to run the legacy installer to install the V9 plugins.  Then run Wave's Central to install the V10 plugins.  This may require you know exactly which plugins you have V9 licenses for and which you have V10 licenses for and instruct the legacy installer to only install those V9 plugins you have licenses for.
 
You will then need to (using Wave Central) download the licenses for both the V9 and V10 plugins to the new machine.  If you store your licenses on a USB thumb drive (I really recommend this) then you just need to move the thumb drive.  If you don't, you'll need to transfer the licensees back to Waves Cloud and then download them on the new machine.
 
This might be very painful and encourage you to pay the crazy WUP, but I don't think you need too and would be better off just dealing with the install dance.

Thanks Matt.
 
The WUP price for me came to $458 which I am not about to do any time soon.
 
I was tempted by the Gold --> Platinum for around $91 which would renew my WUP on those plugins but I would rather spend the money on OTS guitars this month :)

I did the Gold+Renmax+some random spare plugins upgrade to Diamond when V10 shipped, was a pretty good deal.  Though the Horizon deal they just offered was perhaps better. 
 
This all leads me to my new rule: remember always wait, Waves plugins will always go down in price. 
 
That upgrade brought over almost everything I care about to V10 though.  The rest are just random things they will never update.  I may pay the WUP on NX because I use it with headphones, but I don't see any value in the V10 versions of anything else I still have stuck at V9.
 
Of course if they were to add some scaling/resizing features I'd most likely upgrade or WUP everything.