diff --git a/README.md b/README.md
index 5faf5d9de..5e67483d6 100644
--- a/README.md
+++ b/README.md
@@ -93,7 +93,7 @@ # Step 3: Clone the repository to your local machine, and install it.
 
     - **Install the Required Browsers**
 
-    to support PDF conversion, had better install Chrominum.
+    to support PDF conversion, please install Chrominum.
 
     ```bash
     playwright install --with-deps chromium
@@ -114,18 +114,20 @@ # Step 3: Clone the repository to your local machine, and install it.
     pip install pyppeteer
     ```
 
-    - **Install the Required Browsers**
+    - **Use your own Browsers**
 
-    ```bash
-    pyppeteer-install
-    ```
-
-    pyppeteer alow you use already installed browsers, if you do not want to run the above command, please set the following envirment
+    pyppeteer alow you use installed browsers,  please set the following envirment
     
     ```bash
     export PUPPETEER_EXECUTABLE_PATH = /path/to/your/chromium or edge or chrome
     ```
 
+    please do not use this command to install browser, it is too old
+
+    ```bash
+    pyppeteer-install
+    ```
+
     - **modify `config.yaml`**
 
     uncomment MERMAID_ENGINE from config.yaml and change it to `pyppeteer`
diff --git a/metagpt/utils/common.py b/metagpt/utils/common.py
index 99038dc64..5f94de066 100644
--- a/metagpt/utils/common.py
+++ b/metagpt/utils/common.py
@@ -192,6 +192,7 @@ class CodeParser:
             logger.error(f"{pattern} not match following text:")
             logger.error(text)
             # raise Exception
+            return ""
         return code
 
     @classmethod
diff --git a/metagpt/utils/mmdc_pyppeteer.py b/metagpt/utils/mmdc_pyppeteer.py
index e6986bc76..f3e00d053 100644
--- a/metagpt/utils/mmdc_pyppeteer.py
+++ b/metagpt/utils/mmdc_pyppeteer.py
@@ -34,10 +34,15 @@ def mermaid_to_file(mermaid_code, output_file_without_suffix, width, height):
 
     async def mermaid_to_file0(mermaid_code, output_file_without_suffix, width=2048, height=2048, suffixes=['png', 'svg', 'pdf'])-> int:
         __dirname = os.path.dirname(os.path.abspath(__file__))
-        browser = await launch(headless=True,
-                            executablePath=os.getenv('PUPPETEER_EXECUTABLE_PATH',"/opt/homebrew/bin/chromium"),
-                            args=['--disable-extensions',"--no-sandbox"] 
-                            )
+        executablePath = os.getenv('PUPPETEER_EXECUTABLE_PATH',"") 
+        if executablePath:
+            browser = await launch(headless=True,
+                                executablePath=executablePath,
+                                args=['--disable-extensions',"--no-sandbox"] 
+                                )
+        else:
+            print("Please set the environment variable:PUPPETEER_EXECUTABLE_PATH.")
+            return -1
         page = await browser.newPage()
         device_scale_factor = 1.0