Please help me resolve these errors related to shaders.

"WARNING: Shader Unsupported: 'Standard' - Pass 'FORWARD' has no vertex shader WARNING: Shader Unsupported: 'Standard' - Pass 'FORWARD_DELTA' has no vertex shader WARNING: Shader Unsupported: 'Standard' - Pass 'SHADOWCASTER' has no vertex shader WARNING: Shader Unsupported: 'Standard' - All passes removed"

From the above errors about shaders. Can someone help to resolve t$$anonymous$$s issue?