Can't load plugin - Not enough DSP

I’m trying to load a Yamaha amp plugin on my monitor mixer to track a guitar and I’m getting the message “Can’t load plugin, not enough DSP, try using less plugins”.
I don’t have any other plugins loaded. If I load a channel strip, that will work.
I just loaded the default stock settings, running at 44.1 buffer set to 256.

What could be causing this?

I’m really sorry I can’t remember how I fixed this, but I did. It was a setting in Cubase, I believe in the interface area, it was clicking one thing on or off. I know this is a pain answer but it’s an easy fix. I’ll take a look soon and see if I can find it.