Luoshuang's GPULightmass

Hi Guys,

Can Any One Please Help, Its My First Time Using Gpu Lightmass 4.26 And When Starting The Light Bake Process From Build Light Only, It Gives Me An Error (Invalid Device Symbol) . And It Stops Baking The Light,
And When I attempt To Bake It From Gpu Light Mass Dialog Box, There Is A Message That It Requires Ray Tracing To Be Enabled, Knowing That I Have Enabled It From Project Settings,

Iam Running UR4.26, Nvidia Quadro k4200, Two Processors Intel Xeon x5675