Please note that Cubase Elements 9 is a 64-bit application and only supports 64-bit plugin versions.
My recommendation is to check that those plug-ins have not been blacklisted by the Plug-In Sentinel (Devices → Plug-In Manager → Blacklist). You can reactivate the plug-ins that cause issues under your own risk. By clicking on a blacklisted plug-in, a “Reactivate” button should appear below.
More details about the Sentinel can be found here: https://helpcenter.steinberg.de/hc/en-us/articles/207348390-Plug-in-Sentinel-for-Cubase-9