How to install MIDI plugins?

I’m trying to install VST MIDI plugins. I have the .dll files in a folder, and I added the folder to the VST 2 file path, but Cubase doesn’t recognize the plugins. They don’t show up on either the Plugins list or the MIDI Plugins list.

How can I get these plugins to work on Cubase? I have Cubase Artist 6 on Windows 10.