uninstall them from Library manager
I’m having a similar problem (on macOS) with Cubase 11.0.40. 
However, the “More Details…” button opens my browser to a 404 page, and I don’t find any of those files in Library Manager. If I search in /LibraryApplication Support/Steinberg/Content I find some files that look like they could be relevant, but I have no idea for sure and I don’t want to mess up my installation.
% find . -name \*Prime\*
./VST Sound/ADD_SMT_150_Prime_Cuts.vstsound
./Groove Agent/VST Sound/FCP_SMT_740_GA_Prime_Cuts_SP.vstsound
and so on…
I’m not even sure if I should have these licenses or not!
None of the libraries from your screenshot are part of Cubase. They are mostly for Halion 6, Halion Sonic 3 and a couple of Groove Agent expansions. So yes, you need a license for those.
Hi,
You would need to buy dedicated licence for every single listed product. These are not part of Cubase licence.
Uninstall them by using Steinberg Library Manager, please.
I never purchased Halion. Maybe I had a trial license at some point? I do seem to have Halion SE which I think is free with Cubase?
Anyway, Library Manager is a terrible tool for removing things. For example, if I want to remove HALion Symphonic Orchestra Factory Presets 01 because I don’t have a license for it, Library Manager will only let me remove all of those VSTs, even the ones for HALion Sonic SE. I think it’s better to just move that VST out of the way using the terminal. Or at least that’s what I’m going to try to do and see if it works.
And then you still have to remove them once Cubase 11 starts up. 
Even worse, if I try to search for Ethno to remove that VST, Library Manager doesn’t even come back with any search results. So really the only way to clean all this stuff up is from the terminal.
This is the best I’ve been able to whittle it down to. I just cannot find this content. Even Cubase 11’s built-in plugin manager can’t find everything. It seems like there are at least three different views of your installed plugins: 1) Library Manager; 2) Plugin Manager; 3) Cubase start up. That doesn’t even count what you can or can’t find at the terminal or Spotlight.
For example, I can’t find “HS3” anywhere and I have no idea what the path it things is for “HALion Presets 01”, or the Sonic Factory presets it can’t find. Oh well, I guess this is as clean an environment as I’m going to get (after two hours of messing with this stuff). Sure would be nice if Steinberg got their act together on this.
Hi,
These are not plug-ins, these are libraries. So you should be able to find them in the Steinberg Library Manager.
In the Steinberg Library Manager click to the HALION button on the top. You will see HALion Sonic Factory Content. Remove it.
In this dialog, you can also click the More Details… button. As far as I know, the internet browser window appears with the hint, where to find these files.
These files are usually located here:
Drive C: / Users / Username / AppData / Roaming / Steinberg / Content / HALion or VST Sound or Groove Agent or another Drive if you have chosen this option …