Korg Lecagy Collection instruments not found?!

Strange thing after installing the latest Logic Pro X (10.3) and MainStage (3.2.4) I also had to reinstall the Korg Legacy Collection. Before the fresh install, the plugs would show up in the Plug-in Manager but wasn't validated correctly. After reinstall and rescan/reset those plugs (M1, Mono/Poly, Wavestation, MS-20, MDX, Polysix & Legacy Cell) they all became successfully validated.....and showed up i Logic - working :-) But in MainStage they will not show up in the AU Instrument list/menu....?! Not the KORG-folder at all. Is there any necessary reset-routine to refresh this menu? Or trash the pref's?

In advance - thank you for helping.