diff --git a/src/charts/heatmap.js b/src/charts/heatmap.js
index 6d96d600..3ce75cf4 100644
--- a/src/charts/heatmap.js
+++ b/src/charts/heatmap.js
@@ -492,7 +492,7 @@ export default function heatMap(parent, chartGroup) {
     rows = _rowScale.domain(rows)
     cols = _colScale.domain(cols)
     _chart.dockedAxesSize(_chart.getAxisSizes(cols.domain(), rows.domain()))
-    let rowCount = rows.domain().length,
+    const rowCount = rows.domain().length,
       colCount = cols.domain().length,
       availWidth = _chart.width() - _dockedAxesSize.left,
       availHeight = _chart.height() - _dockedAxesSize.bottom,
diff --git a/src/charts/row-chart.js b/src/charts/row-chart.js
index daa33901..b60a4150 100644
--- a/src/charts/row-chart.js
+++ b/src/charts/row-chart.js
@@ -560,7 +560,7 @@ export default function rowChart(parent, chartGroup) {
   /* --------------------------------------------------------------------------*/
 
   function translateX(d) {
-    let x = _x(_chart.cappedValueAccessor(d)),
+    const x = _x(_chart.cappedValueAccessor(d)),
       x0 = rootValue(),
       s = x > x0 ? x0 : x
     return "translate(" + s + ",0)"
diff --git a/src/mixins/cap-mixin.js b/src/mixins/cap-mixin.js
index e955bf51..61d6b5fa 100644
--- a/src/mixins/cap-mixin.js
+++ b/src/mixins/cap-mixin.js
@@ -21,7 +21,7 @@ export default function capMixin(_chart) {
   let _othersLabel = "Others"
 
   let _othersGrouper = function(topRows) {
-    let topRowsSum = d3.sum(topRows, _chart.valueAccessor()),
+    const topRowsSum = d3.sum(topRows, _chart.valueAccessor()),
       allRows = _chart.group().all(),
       allRowsSum = d3.sum(allRows, _chart.valueAccessor()),
       topKeys = topRows.map(_chart.keyAccessor()),
diff --git a/src/mixins/coordinate-grid-mixin.js b/src/mixins/coordinate-grid-mixin.js
index 93680812..3d8f23df 100644
--- a/src/mixins/coordinate-grid-mixin.js
+++ b/src/mixins/coordinate-grid-mixin.js
@@ -723,7 +723,7 @@ export default function coordinateGridMixin (_chart) {
       if (_y === undefined) {
         _y = d3.scale.linear()
       }
-      let min = _chart.yAxisMin() || 0,
+      const min = _chart.yAxisMin() || 0,
         max = _chart.yAxisMax() || 0
       _y.domain([min, max]).rangeRound([_chart.yAxisHeight(), 0])
     }
@@ -1363,7 +1363,7 @@ export default function coordinateGridMixin (_chart) {
 
   // borrowed from Crossfilter example
   _chart.resizeHandlePath = function (d) {
-    let e = Number(d === "e"),
+    const e = Number(d === "e"),
       x = e ? 1 : -1,
       y = brushHeight() / 3
     return (
diff --git a/src/mixins/coordinate-grid-raster-mixin.js b/src/mixins/coordinate-grid-raster-mixin.js
index 56aed5ae..4cb0a020 100644
--- a/src/mixins/coordinate-grid-raster-mixin.js
+++ b/src/mixins/coordinate-grid-raster-mixin.js
@@ -214,7 +214,7 @@ export default function coordinateGridRasterMixin (_chart, _mapboxgl, browser) {
   }
 
   _chart.unproject = function (pt) {
-    let xscale = _chart.x(),
+    const xscale = _chart.x(),
       yscale = _chart.y()
     const x = (xscale ? xscale.invert(pt.x) : 0)
     const y = (yscale ? yscale.invert(pt.y) : 0)
@@ -1404,7 +1404,7 @@ axis in dc.js is simply an instance of a [d3 axis
 
   // borrowed from Crossfilter example
   _chart.resizeHandlePath = function (d) {
-    let e = Number(d === "e"),
+    const e = Number(d === "e"),
       x = e ? 1 : -1,
       y = brushHeight() / 3
     return "M" + (0.5 * x) + "," + y + "A6,6 0 0 " + e + " " + (6.5 * x) + "," + (y + 6) + "V" + (2 * y - 6) + "A6,6 0 0 " + e + " " + (0.5 * x) + "," + (2 * y) + "Z" + "M" + (2.5 * x) + "," + (y + 8) + "V" + (2 * y - 8) + "M" + (4.5 * x) + "," + (y + 8) + "V" + (2 * y - 8)
diff --git a/src/mixins/d3.box.js b/src/mixins/d3.box.js
index 366ad860..69dad05d 100644
--- a/src/mixins/d3.box.js
+++ b/src/mixins/d3.box.js
@@ -17,7 +17,7 @@ import d3 from "d3"
     function box(g) {
       g.each(function(d, i) {
         d = d.map(value).sort(d3.ascending)
-        let g = d3.select(this),
+        const g = d3.select(this),
           n = d.length,
           min = d[0],
           max = d[n - 1]
@@ -26,7 +26,7 @@ import d3 from "d3"
         const quartileData = (d.quartiles = quartiles(d))
 
         // Compute whiskers. Must return exactly 2 elements, or null.
-        let whiskerIndices = whiskers && whiskers.call(this, d, i),
+        const whiskerIndices = whiskers && whiskers.call(this, d, i),
           whiskerData = whiskerIndices && whiskerIndices.map(i => d[i])
 
         // Compute outliers. If no whiskers are specified, all data are 'outliers'.
diff --git a/src/mixins/raster-layer.js b/src/mixins/raster-layer.js
index ecbcaf40..d1f94472 100644
--- a/src/mixins/raster-layer.js
+++ b/src/mixins/raster-layer.js
@@ -27,6 +27,8 @@ const validLayerTypes = [
 ]
 
 const { getImageSize, replaceAsync, parseUrlParts } = utils
+const MISSING_HIT_TEST_COLUMN_ERROR =
+  "$HEAVYAI_ERROR_COLUMN_NOT_FOUND_IN_HIT_TEST_CACHE$"
 
 export default function rasterLayer(layerType) {
   const _layerType = layerType
@@ -355,7 +357,11 @@ export default function rasterLayer(layerType) {
     const columnSet = new Set(popupColumns)
     for (const key in data) {
       if (columnSet.has(key)) {
-        newData[key] = data[key]
+        // check for missing hit test cache columns and substitute readable message
+        newData[key] =
+          data[key] === MISSING_HIT_TEST_COLUMN_ERROR
+            ? "Column Not Found"
+            : data[key]
         data[key] instanceof Date ? moment(data[key]).utc() : data[key]
 
         if (typeof chart.useLonLat === "function" && chart.useLonLat()) {