Variaudio causes Cubase freeze in 48Hz?


I’ve just started work on a live mix recorded multi track on an Allen & Heath QU16 mixer. The QU16 only records at 48Hz so I have the Cubase project set up at 48Hz.
Everything has been working great until I tried to use Variaudio! Every time I try to use the pitch and warp function Cubase freezes part way through. I tried loading older 44.1Hz projects and Variaudio works absolutely fine.

Any ideas?