Hmmm, I just checked 5.6.1 and ds standard shaders work fine ( Imported from 5.6.0f3 version ) That line you changed need to be AdditiveLight( IN_LIGHTDIR_FWDADD(i), LIGHT_ATTENUATION(i)); in StandardDSCoreForward.cginc for additional light pass. You can look in built in shaders for 5.6.1f1. What error does it display? Have you tried creating new project with default settings and importing again? I just submitted update to fix shadows for two face cutout shaders.