diff --git a/notes.md b/notes.md
index ddb4e049..f0f6d97d 100644
--- a/notes.md
+++ b/notes.md
@@ -62,11 +62,11 @@
 * `B` clicking on a pop-op should pin it until clicked or [esc]
 * `B` need to force cut line at synthetic z bottom (midlines, etc)
 * `B` non-clear-voids duplicates thru-holes
-* `B` failure to go *up* when moving between parts?
 * `B` starting export during animation unleashes chaos
 * `B` climb vs conventional not fully consistent after refactor
 * `B` outside cutting direction in roughing mode inverted
 
+* `F` import SVG into a path that can be overlaid onto a 3D mesh (laser?)
 * `F` intelligently turn circle hole pocket clear into spiral down
 * `F` trace follow hole that matches endmill should turn into a drill op
 * `F` add climb/conventional into each operation
diff --git a/src/kiri/client.js b/src/kiri/client.js
index 9dd2af07..7f6a660b 100644
--- a/src/kiri/client.js
+++ b/src/kiri/client.js
@@ -70,9 +70,9 @@ KIRI.work = {
             worker.terminate();
         }
 
-        for (let key in slicing) {
-            slicing[key]({error: "cancelled slicing"});
-        }
+        // for (let key in slicing) {
+        //     slicing[key]({error: "cancelled slicing"});
+        // }
 
         syncd = {};
         slicing = {};
@@ -188,6 +188,9 @@ KIRI.work = {
             if (reply.done) {
                 done(reply.output, reply.maxSpeed);
             }
+            if (reply.error) {
+                done(reply);
+            }
         });
     },
 
@@ -199,6 +202,9 @@ KIRI.work = {
             if (reply.done) {
                 ondone(reply.output);
             }
+            if (reply.error) {
+                ondone(null, reply.error);
+            }
         });
     },
 
diff --git a/src/kiri/export.js b/src/kiri/export.js
index a2e047e0..ebecd552 100644
--- a/src/kiri/export.js
+++ b/src/kiri/export.js
@@ -35,9 +35,11 @@
         const gcode = [];
         KIRI.client.export(API.conf.get(), (line) => {
             gcode.push(line);
-        }, (output) => {
+        }, (output, error) => {
             API.hide.alert(alert);
-            if (callback) {
+            if (error) {
+                API.show.alert(error, 5);
+            } else if (callback) {
                 callback(gcode.join('\r\n'), output);
             } else {
                 exportGCodeDialog(gcode.join('\r\n'), output);
@@ -48,8 +50,12 @@
     function callExportLaser(options) {
         KIRI.client.export(API.conf.get(), (line) => {
             console.log({unexpected_line: line});
-        }, (output) => {
-            exportLaserDialog(output);
+        }, (output, error) => {
+            if (error) {
+                API.show.alert(error, 5);
+            } else {
+                exportLaserDialog(output);
+            }
         });
     }
 
@@ -60,9 +66,13 @@
             if (line.data) {
                 preview.push(line.data);
             }
-        }, (output) => {
+        }, (output, error) => {
             API.show.progress(0);
-            KIRI.driver.SLA.printDownload(preview, output, API);
+            if (error) {
+                API.show.alert(error, 5);
+            } else {
+                KIRI.driver.SLA.printDownload(preview, output, API);
+            }
         });
     }
 
diff --git a/src/kiri/main.js b/src/kiri/main.js
index faf632e3..faa320a6 100644
--- a/src/kiri/main.js
+++ b/src/kiri/main.js
@@ -898,9 +898,22 @@
                     }
                     API.event.emit('slice', getMode());
                 }
+                // handle slicing errors
+                if (error && !errored) {
+                    errored = true;
+                    setViewMode(VIEWS.ARRANGE);
+                    alert2(error, 5);
+                    API.show.progress(0);
+                    KIRI.client.restart();
+                    API.event.emit('slice.error', error);
+                }
+                // discard remaining errors
+                if (errored) {
+                    return;
+                }
                 let alert = null;
                 // on the last exit, update ui and call the callback
-                if (--countdown === 0 || error || errored) {
+                if (--countdown === 0) {
                     if (scale === 1 && feature.work_alerts) {
                         alert = API.show.alert("Rendering");
                     };
@@ -923,12 +936,13 @@
                         updateSliderMax(true);
                         setVisibleLayer(-1, 0);
                     });
-                    // mark slicing complete for prep/preview
-                    complete.slice = true;
                     if (scale === 1) {
                         API.show.progress(0);
                     }
+                    // cause visuals to update
                     SPACE.scene.active();
+                    // mark slicing complete for prep/preview
+                    complete.slice = true;
                     API.event.emit('slice.end', getMode());
                     // print stats
                     segtimes.total = Date.now() - now;
@@ -937,16 +951,6 @@
                         callback();
                     }
                 }
-                // handle slicing errors
-                if (error && !errored) {
-                    API.show.progress(0);
-                    API.hide.alert(alert);
-                    errored = true;
-                    setViewMode(VIEWS.ARRANGE);
-                    setOpacity(color.model_opacity);
-                    platform.deselect();
-                    alert2(error, 1);
-                }
             }, function(update, msg) {
                 if (msg && msg !== lastMsg) {
                     let mark = Date.now();
@@ -1018,7 +1022,17 @@
                 startTime = mark;
             }
             API.show.progress(offset + progress * scale, message);
-        }, function (oldout, maxSpeed) {
+        }, function (reply, maxSpeed) {
+            // handle worker errors
+            if (reply && reply.error) {
+                alert2(reply.error, 5);
+                setViewMode(VIEWS.ARRANGE);
+                API.event.emit('preview.error', reply.error);
+                API.show.progress(0);
+                SPACE.update();
+                return;
+            }
+
             if (lastMsg) {
                 segtimes[`${segNumber++}_${lastMsg}`] = Date.now() - startTime;
             }
diff --git a/src/kiri/worker.js b/src/kiri/worker.js
index da70b9e4..77c363d8 100644
--- a/src/kiri/worker.js
+++ b/src/kiri/worker.js
@@ -159,35 +159,30 @@ KIRI.worker = {
             last = time(),
             now;
 
-        try {
-            widget.slice(settings, function(error) {
-                if (error) {
-                    send.data({error: error});
-                } else {
-                    const slices = widget.slices || [];
-                    send.data({send_start: time()});
-                    send.data({
-                        stats: widget.stats,
-                        slices: slices.length,
-                    });
-                    slices.forEach(function(slice,index) {
-                        const state = { zeros: [] };
-                        send.data({index: index, slice: slice.encode(state)}, state.zeros);
-                    })
-                    send.data({send_end: time()});
-                }
-                send.done({done: true});
-            }, function(update, msg) {
-                now = time();
-                if (now - last < 10 && update < 0.99) return;
-                // on update
-                send.data({update: (0.05 + update * 0.95), updateStatus: msg});
-                last = now;
-            });
-        } catch (error) {
-            send.data({error: error.toString()});
-            console.log(error);
-        }
+        widget.slice(settings, function(error) {
+            if (error) {
+                send.data({error: error});
+            } else {
+                const slices = widget.slices || [];
+                send.data({send_start: time()});
+                send.data({
+                    stats: widget.stats,
+                    slices: slices.length,
+                });
+                slices.forEach(function(slice,index) {
+                    const state = { zeros: [] };
+                    send.data({index: index, slice: slice.encode(state)}, state.zeros);
+                })
+                send.data({send_end: time()});
+            }
+            send.done({done: true});
+        }, function(update, msg) {
+            now = time();
+            if (now - last < 10 && update < 0.99) return;
+            // on update
+            send.data({update: (0.05 + update * 0.95), updateStatus: msg});
+            last = now;
+        });
     },
 
     prepare: function(data, send) {
@@ -593,20 +588,25 @@ self.onmessage = function(e) {
         };
 
     if (run) {
-        let time_xfer = (time_recv - msg.time),
-            output = run(msg.data, send),
-            time_send = time(),
-            time_proc = time_send - time_recv;
+        try {
+            let time_xfer = (time_recv - msg.time),
+                output = run(msg.data, send),
+                time_send = time(),
+                time_proc = time_send - time_recv;
 
-        if (output) self.postMessage({
-            seq: msg.seq,
-            task: msg.task,
-            time_send: time_xfer,
-            time_proc: time_proc,
-            // replaced on reply side
-            time_recv: time(),
-            data: output
-        });
+            if (output) self.postMessage({
+                seq: msg.seq,
+                task: msg.task,
+                time_send: time_xfer,
+                time_proc: time_proc,
+                // replaced on reply side
+                time_recv: time(),
+                data: output
+            });
+        } catch (wrkerr) {
+            console.log({wrkerr});
+            send.done({error: wrkerr.toString()});
+        }
     } else {
         console.log({kiri_msg:e});
     }
diff --git a/src/mode/fdm/prepare.js b/src/mode/fdm/prepare.js
index 7382caf2..2366ed00 100644
--- a/src/mode/fdm/prepare.js
+++ b/src/mode/fdm/prepare.js
@@ -20,7 +20,6 @@
      */
     FDM.prepare = function(widgets, settings, update) {
         settings = FDM.fixExtruders(settings);
-
         let render = settings.render !== false,
             { device, process, controller, bounds, mode } = settings,
             output = [],
diff --git a/web/kiri/index.html b/web/kiri/index.html
index ef601e46..502dfc1a 100644
--- a/web/kiri/index.html
+++ b/web/kiri/index.html
@@ -3,7 +3,7 @@
 <head>
     <meta charset="UTF-8">
     <meta name="author" content="Stewart Allen">
-    <meta name="keywords" content="3d slicer,slicer,3d slicing,cnc,cam,toolpaths,toolpath generation,kiri,kirimoto,kiri:moto,gcode,cura,simplify 3d,prusaslicer,fdm,sla" />
+    <meta name="keywords" content="3d slicer,chromebook,slicer,3d slicing,cnc,cam,toolpaths,toolpath generation,kiri,kirimoto,kiri:moto,gcode,cura,simplify 3d,prusaslicer,fdm,sla" />
     <meta name="copyright" content="stewart allen [sa@grid.space]">
     <meta name="description" content="Browser-based 3D slicer, gcode and CNC toolpath generator">
     <meta property="og:description" content="Kiri:Moto is a unique 3D slicer that runs entirely in browser and creates output for your favorite maker tools: 3D Printers, CNC Mills and Laser Cutters.">