If you get an error during installation of an Omnisphere soundset, such as “this package does not contain any files” then move the .omnisphere file into the Spectrasonics folder itself and try installing it from there. On PC the Spectrasonics folder could be C: ProgramData/Spectrasonics and on Mac it’s likely Users/Username/Library/Application Support/Spectrasonics.

If you cannot see the ProgramData path above on PC then it’s because it’s a hidden folder, refer to the page below on how to show hidden folders:

https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files