Some of my plugins got blacklisted, and after trying everything including 'Reset Blacklist' button, reinstalling plugins, restarting scanning S1-4 etc - I found the following solution to make them appear again.
NOTE: Below is the answer of wes8 if you want to reinstall S1 - My solution is if you are comfortable with quickly editing a file in a text editor:
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- Open Studio One 4
- In the menu bar go to Help --> Open Settings Folder
- Look inside the "x64" folder for the Plugins-en.settings file [MAKE A COPY just in case]
- Open the Plugins-en.settings file in any text editor
- CLOSE S1 app
- In your editor search for your plugin for example "Tube Delay"
You might now find an entry for VST2 and/or VST3 depending what you installed:
<Section path="B6B24A14/Tube Delay.dll"> AND/OR <Section path="0CE10D5D/Tube Delay.vst3">
Directly underneath one of these lines you will find this:
<Attributes numClasses="0">
CHANGE TO <Attributes numClasses="1">
IF you now go "FInd next" in your editor you might also find pathes - you can ignore them:
<Url type="1" url="file:///C:/Program Files/Vstplugins/Softube/Tube Delay.dll"/>
<Url type="1" url="file:///C:/Program Files/Common Files/VST3/Tube Delay.vst3"/>
REPEAT for all your plugins.
SAVE the file
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If you now open S1 your plugins should all show.
I think after a blacklist these plugins stay hidden and the 'Reset Blacklist' fails to make the changes to make them appear again.