diff --git a/src/mode/fdm/slice.js b/src/mode/fdm/slice.js
index 02ff1b98..df007d4d 100644
--- a/src/mode/fdm/slice.js
+++ b/src/mode/fdm/slice.js
@@ -695,7 +695,11 @@
      * @param {Polygon[]} polys
      */
     function addSolidFills(slice, polys) {
-        slice.solids.appendAll(polys);
+        if (slice.solids) {
+            slice.solids.appendAll(polys);
+        } else if (polys && polys.length) {
+            console.log({no_solids_in: slice, for: polys})
+        }
     };
 
     /**
diff --git a/src/mode/sla/export.js b/src/mode/sla/export.js
index a1461877..fd41292d 100644
--- a/src/mode/sla/export.js
+++ b/src/mode/sla/export.js
@@ -266,7 +266,7 @@
             layerBytes = width * height,
             coded;
 
-        if (legacy) {
+        if (SLA.legacy) {
             let converted = conf.lines.map((line, index) => {
                 let count = line.length / 4;
                 let bits = new Uint8Array(line.length / 4);
diff --git a/src/mode/sla/slice.js b/src/mode/sla/slice.js
index 9341a674..cfbc5462 100644
--- a/src/mode/sla/slice.js
+++ b/src/mode/sla/slice.js
@@ -584,7 +584,7 @@
         }
 
         fill = POLY.trimTo(fill, slice.tops.map(t => t.poly));
-        fill = POLY.union(slice.unioned.appendAll(fill));
+        fill = POLY.union(slice.unioned.appendAll(fill),0,true);
 
         slice.unioned = fill;
     }