I thought I'd just post a link to the main forum where I've described a very serious bug introduced with the latest update of SampleTank3. It's been confirmed by another user and also by a user on the Presonus Studio One forum.
If you haven't already applied 3.5.1 then DON'T! It only makes changes to enable their new 'Custom Shop' feature.
I'll update when I get a response from my IK support ticket. 
http://forum.cakewalk.com/Sampletank3-update-351-Could-someone-check-a-possible-major-bug-for-me-m3216016.aspx

Oh no.........Ik, Ik, Ik.........why do you keep doing this to us?? ...........going 2 steps forward and one step behind (or just missing the step??)
 
Hopefully, an update to the last "updated patch" will be in the works.....

Thanks for the heads up.

There's more than just Custom Shop functionality added in this update, there are fixes.  To elaborate - there are minor issues in where the preset browser section jumps to only after doing a search so if that affects one's workflow in a huge way then yes the issue is impactful to you otherwise the update is good to install (especially if you were experiencing lag switching between pages and other issues).  Also note that standalone ST3 Mac users are not affected, as I've been told.  I hope that provides some context to all, thank you for reading.
 
Edit - Potential workaround support has tried with Sonar too (I tested with Standalone first): Click the 'x' to clear out of the search field (and this closes your search), and all loaded sounds would trigger back to their location when clicked on.

Although a nuisance (I like to do the same thing, auditioning alternate related patches), it's still a bit of a stretch to call this a "major" or "very serious" bug.
 
A major bug is one that prevents you from utilizing an important feature, and which has no convenient workaround.
 
If I understand you correctly, this one does have a convenient workaround: use the VST2 version. We've seen so many plugins fail in their VST3 implementations that it only makes sense to stick to the tried-and-true unless there's a compelling reason not to. In the case of ST3, there is no compelling reason to use the VST3 version.
 
 

Sorry, Peter but my tests show the big problem is that ST3 forgets the locations of all loaded patches if the project is saved, closed and then reopened inside the host (Sonar and Studio One).  The same thing happens if you save the loaded patches as a Multi.
Standalone behaves the same for Multis, e.g. open, load some patches, save the scene as a test multi.  Close standalone. Reopen. Load test Multi. Locations not highlighted when any track/patch is clicked on.
 
I'm eagerly awaiting Support's response to my ticket. This is really bad for me as I use ST3 a lot. If a fix is going to be a while then I need to know from them how to roll back in the meantime to 3.5.

bitflipper
...A major bug is one that prevents you from utilizing an important feature, and which has no convenient workaround.
 If I understand you correctly, this one does have a convenient workaround: use the VST2 version....
 

Behaves the same for me in VST2.  (In Sonar and Studio One).

Ergo major?

Sorry, I thought you said VST2 was not a problem. At any rate, I'm sure it'll be a quick fix.
 

Update:  IK confirmed to me they can reproduce, and a fix update should be along in a couple of weeks.
 
John

Thanks for pushing this to get a fix and for the update.