Problem with pick_object

function setup_click_on_object() {
	_canvas_elem.addEventListener("mousedown", function(e){click_on_object(e)}, false);
	
	function click_on_object(e) {
		console.log("Clicked");
		// if (_disable_interaction)
        // return;

		if (e.preventDefault)
			e.preventDefault();
		
		var canvas_xy = m_cont.client_to_canvas_coords(e.clientX, e.clientY, _vec2_tmp);
		
		var x = canvas_xy[0];
		var y = canvas_xy[1];		
		
		var obj = m_scs.pick_object(x, y);
		
		if (obj)
			console.log(m_scs.get_object_name(obj));
		}
}

TypeError: Argument 2 is not valid for any of the 2-argument overloads of WebGLRenderingContext.uniform3fv.

        case "u_color_id":
            fun = function(gl, loc, obj_render, batch) {
                gl.uniform3fv(loc, obj_render.color_id);
            }