[Solved]-How to remove outer shadow when hovered from highcharts JAVASCRIPT-Highcharts

in your tooltip settings:

tooltip: {
    formatter: function() {
        return '<b>'+ this.point.name +'</b>: '+ this.y;
    }
},

you need to add shadow: false

tooltip: {
  formatter: function() {
        return '<b>'+ this.point.name +'</b>: '+ this.y;
  },
  shadow: false
}

also, in your plotoptions you need to essentially remove the marker layer in the object, like so:

plotoptions: {        
    series: {
        states: {
            hover: {
                enabled: false
            }
        }
    },

(working fiddle)