diff --git a/lama_cleaner/server.py b/lama_cleaner/server.py
index 68d63e0..8fa9f82 100644
--- a/lama_cleaner/server.py
+++ b/lama_cleaner/server.py
@@ -148,9 +148,10 @@ def save_image():
     input = request.files
     filename = request.form["filename"]
     origin_image_bytes = input["image"].read()  # RGB
-    ext = get_image_ext(origin_image_bytes)
+    # ext = get_image_ext(origin_image_bytes)
+    ext = "png"
     image, alpha_channel, exif_infos = load_img(origin_image_bytes, return_exif=True)
-    save_path = str(global_config.output_dir / filename)
+    save_path = (global_config.output_dir / filename).with_suffix(f".{ext}")
 
     if alpha_channel is not None:
         if alpha_channel.shape[:2] != image.shape[:2]:
@@ -159,7 +160,7 @@ def save_image():
             )
         image = np.concatenate((image, alpha_channel[:, :, np.newaxis]), axis=-1)
 
-    pil_image = Image.fromarray(image)
+    pil_image = Image.fromarray(image).convert("RGBA")
 
     img_bytes = pil_to_bytes(
         pil_image,
@@ -167,8 +168,11 @@ def save_image():
         quality=global_config.image_quality,
         exif_infos=exif_infos,
     )
-    with open(save_path, "wb") as fw:
-        fw.write(img_bytes)
+    try:
+        with open(save_path, "wb") as fw:
+            fw.write(img_bytes)
+    except:
+        return f"Save image failed: {traceback.format_exc()}", 500
 
     return "ok", 200
 
@@ -551,6 +555,9 @@ def start(
     if output_dir:
         output_dir = output_dir.expanduser().absolute()
         logger.info(f"Image will auto save to output dir: {output_dir}")
+        if not output_dir.exists():
+            logger.info(f"Create output dir: {output_dir}")
+            output_dir.mkdir(parents=True)
         global_config.output_dir = output_dir
 
     global_config.model_manager = ModelManager(
diff --git a/web_app/src/components/Editor.tsx b/web_app/src/components/Editor.tsx
index 50f256c..225d0f0 100644
--- a/web_app/src/components/Editor.tsx
+++ b/web_app/src/components/Editor.tsx
@@ -501,13 +501,17 @@ export default function Editor(props: EditorProps) {
     }
   )
 
-  function download() {
+  const download = async () => {
     if (file === undefined) {
       return
     }
     if (enableAutoSaving && renders.length > 0) {
       try {
-        downloadToOutput(renders[renders.length - 1], file.name, file.type)
+        await downloadToOutput(
+          renders[renders.length - 1],
+          file.name,
+          file.type
+        )
         toast({
           description: "Save image success",
         })
diff --git a/web_app/src/lib/api.ts b/web_app/src/lib/api.ts
index 0359eb3..02db905 100644
--- a/web_app/src/lib/api.ts
+++ b/web_app/src/lib/api.ts
@@ -81,7 +81,7 @@ export default async function inpaint(
     "controlnet_conditioning_scale",
     settings.controlnetConditioningScale.toString()
   )
-  fd.append("controlnet_method", settings.controlnetMethod.toString())
+  fd.append("controlnet_method", settings.controlnetMethod?.toString())
 
   // PowerPaint
   if (settings.showExtender) {
@@ -213,6 +213,7 @@ export async function downloadToOutput(
       method: "POST",
       body: fd,
     })
+    console.log(res.ok)
     if (!res.ok) {
       const errMsg = await res.text()
       throw new Error(errMsg)