Install KORG Collection 2 plugins from the Splice desktop client and restart your machine.
To get KORG Collection 2 plugins up and running in Ableton you need to check Ableton's AU/VST settings.
Navigate to :
File and Folder
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 your KORG Collection 2 plugin. By default the Windows installation path is: