I'm a Mario fan, and I took the time to create Peach's Castle in ClassicCube. After finishing it, I added my texture pack and it looked amazing! But something was missing: a playable Mario in the ClassicCube world I created. I downloaded the plugin, but it didn't work. It threw up an invalid Win32 error. Even installing the 64-bit or 32-bit version, I always get the same error.

what windows version are you trying to use the plugin on?

I use a toaster with Windows 7 64-bit.