I've found 2 problems since I've updated to Reaktor 6.5 VST2.
1.- When I load an ensemble (Prism, Monark, Trk-01, Carbon...) my DAW freezes for 15-30 seconds. I can see the interfaze of the loaded plugin & I can play sounds. It's not a CPU freeze, song/audio keeps playing.
2.- Dropdown menus don't show. Both Reaktor plugin interface & ensemble interface.
I've downgraded to 6.3 now and the dropdown menus are showing but the freeze is still there (I'll clean Cell cache right now)
3.- The application version 6.3 works flawlessly. No freeze on load.
Windows 10 up to date, Ryzen R5 5600, 24Gb RAM, Fast SSD...