diff --git a/js/kiri-driver-fdm.js b/js/kiri-driver-fdm.js
index 436c69d5..97b841a8 100644
--- a/js/kiri-driver-fdm.js
+++ b/js/kiri-driver-fdm.js
@@ -107,6 +107,8 @@ let gs_kiri_fdm = exports;
         }
 
         function onSliceDone(slices) {
+            slices = slices.filter(slice => slice.tops.length);
+
             widget.slices = slices;
 
             if (!slices) return;
diff --git a/js/kiri-driver-sla.js b/js/kiri-driver-sla.js
index 2469abd3..8492a089 100644
--- a/js/kiri-driver-sla.js
+++ b/js/kiri-driver-sla.js
@@ -59,7 +59,8 @@ let gs_kiri_sla = exports;
         SLICER.sliceWidget(widget, {
             height: process.slaSlice || 0.05
         }, function(slices) {
-            widget.slices = slices.filter(slice => slice.tops.length);
+            slices = slices.filter(slice => slice.tops.length);
+            widget.slices = slices;
             // reset for solids and support projections
             slices.forEach(function(slice) {
                 slice.invalidateFill();
diff --git a/js/kiri-slice.js b/js/kiri-slice.js
index 45ba7c3e..f3385a94 100644
--- a/js/kiri-slice.js
+++ b/js/kiri-slice.js
@@ -849,7 +849,7 @@ let gs_kiri_slice = exports;
      * @param {Polygon[]} polys
      */
     PRO.addSolidFills = function(polys) {
-        this.solids.poly.appendAll(polys);
+        if (this.solids.poly) this.solids.poly.appendAll(polys);
     };
 
     /**