I’ve upgraded plugins or reinstalled plugins before and had their name change. Then you get a plugin not found message on older projects when the plugin has just changed name. It happened with Poise. It used to say Steinberg as the manufacturer name then they changed it/fixed it in an update to say their name but it stopped working in older project versions. There should be a way to tell Cubase it’s the same plugin. I just stopped using the plugin eventually.
Also VST3 versions of plugins sometimes have a different name to VST2 versions and Cubase doesn’t know it’s the same plugin so you’re forced to keep both versions of your computer to open older sessions which is annoying because sometimes you accidentally open the vst2 version by mistake instead of the vst3 version.