Install Serato Sample from the Splice desktop client and restart your machine.
To get Serato Sample up and running in Ableton you need to check Ableton's AU/VST settings.
Navigate to :
File and Folder(all Live versions until 10.1)/Plug-ins (Live 10.1 and later)
Make sure "Use AudioUnits/VST" are all checked and hit Rescan.
Windows users will only have the option "VST Plugin Custom Folder", manually navigate to the location you installed Serato Sample. By default the Windows installation path is: