There are two denoising options available for rendering with Arnold:
The OptiX™ Denoiser MultiExcerpt named 'OptiX™ Denoiser ' was not found
The page: Denoising was found, but the multiexcerpt named 'OptiX™ Denoiser ' was not found. Please check/update the page name used in the 'multiexcerpt-include macro.
The Arnold Denoiser MultiExcerpt named 'Arnold Denoiser ' was not found
The page: Denoising was found, but the multiexcerpt named 'Arnold Denoiser ' was not found. Please check/update the page name used in the 'multiexcerpt-include macro.
MultiExcerpt named 'example' was not found
The page: Denoising was found, but the multiexcerpt named 'example' was not found. Please check/update the page name used in the 'multiexcerpt-include macro.