Vertex Fog option causes problem on mobile build.

I have an arch viz project which had a fog material and on mobile I deleted the fog material and cubes it was applied to. When I preview mobile and deploy on mobile I get the message “Project has vertex fog on mobile disabled.” which I go ahead and uncheck “disable vertex fogging on mobile shaders” and rebuild it starts my character in some other unknown location presumably facing down on the ground and unable to move.

Like I said, I’ve deleted any shader I thought was utilizing fog. How do I find any offending shader and why would this kill my player mobility when it was turned off?

Thank you for anyone taking time to read this.