This will happen when NVIDIA GPU drivers for Guppy have not been installed, or have been installed incorrectly.
(Re)installing GPU driver packages should solve this.
Guppy requires an NVIDIA driver of at least version 455, though we recommend the latest version if possible as there can be performance and stability improvements. CUDA Toolkit v11 (v12 is not compatible) is also required.
Please see the Guppy protocol page for more information.