Some plug-ins are not available to load in RX 10. This includes Ozone 10 and Neutron 4.
Due to Steinberg dropping VST2 support, Ozone 10, RX 10, Neutron 4, Symphony 3D, and Stratus 3D are only available in the VST3 format (as well as the AAX and AU formats).
We are currently working on an update for RX 10 to include VST3 compatibility for plug-in hosting and plan to release this feature in the near future. Please keep an eye out for updates in your Product Portal.
Note: if you are using a Mac computer, you can load the AU format of the plug-in in RX 10.