diff --git a/docs/uncompiled/artplayer-tool-thumbnail.js b/docs/uncompiled/artplayer-tool-thumbnail.js
index 5e2846161..7c5d6a613 100644
--- a/docs/uncompiled/artplayer-tool-thumbnail.js
+++ b/docs/uncompiled/artplayer-tool-thumbnail.js
@@ -270,6 +270,8 @@
           sleep(delay).then(function () {
             _this3.emit('video', _this3.video);
           }).catch(function (err) {
+            _this3.emit('error', err.message);
+
             console.error(err);
           });
         }
@@ -309,14 +311,22 @@
         });
         this.processing = true;
         runPromisesInSeries(promiseList).then(function () {
-          sleep(delay * 2).then(function () {
+          return sleep(delay * 2).then(function () {
             _this4.processing = false;
 
             _this4.emit('done');
           }).catch(function (err) {
+            _this4.processing = false;
+
+            _this4.emit('error', err.message);
+
             console.error(err);
           });
         }).catch(function (err) {
+          _this4.processing = false;
+
+          _this4.emit('error', err.message);
+
           console.error(err);
         });
       }
diff --git a/packages/artplayer-tool-thumbnail/src/index.js b/packages/artplayer-tool-thumbnail/src/index.js
index 165a5e78c..5bb56fd86 100644
--- a/packages/artplayer-tool-thumbnail/src/index.js
+++ b/packages/artplayer-tool-thumbnail/src/index.js
@@ -73,6 +73,7 @@ class ArtplayerToolThumbnail extends Emitter {
                     this.emit('video', this.video);
                 })
                 .catch(err => {
+                    this.emit('error', err.message);
                     console.error(err);
                 });
         }
@@ -104,17 +105,21 @@ class ArtplayerToolThumbnail extends Emitter {
         });
         this.processing = true;
         runPromisesInSeries(promiseList)
-            .then(() => {
+            .then(() =>
                 sleep(delay * 2)
                     .then(() => {
                         this.processing = false;
                         this.emit('done');
                     })
                     .catch(err => {
+                        this.processing = false;
+                        this.emit('error', err.message);
                         console.error(err);
-                    });
-            })
+                    }),
+            )
             .catch(err => {
+                this.processing = false;
+                this.emit('error', err.message);
                 console.error(err);
             });
     }