If you do not own any Waves v10 products, downloading the Waveshell is pointless. However, you may be searching for a free alternative to achieve similar sonic results. Here are legitimate free VST3 plugins that rival classic Waves processors:
Waveshell1-VST3 10.0: The Essential Bridge for Legacy Audio Projects
specifically refers to the first or primary Waveshell architecture used for a given generation of plugins. By version 10.0, Waves had refined its VST3 implementation significantly.
If you already own a Waves license for plugins that require version 10.0, follow these steps exactly.
The bottom line: If you cannot afford Waves plugins, use the free alternatives listed above. If you already own them, install the for free via Waves Central.