Resolved on my Windows 10 Pro system by backing up then manually editing the following file to remove all references to Inspirata:
C:\Users\<username>\AppData\Roaming\Presonus\Studio One 5\x64\Plugins-en.settings
The plugin entry should, but in my case did not, contain a List section containing info about the actual plugin.
After making this change, restarting Studio One 5 caused the plugin to be rescanned.
The entry was then written correctly to the settings file, and the plugin is now showing up as expected in Studio One 5.
Cheers,
AR