diff --git a/DrissionPage/__init__.py b/DrissionPage/__init__.py
index 8faccd9..40056cf 100644
--- a/DrissionPage/__init__.py
+++ b/DrissionPage/__init__.py
@@ -14,4 +14,4 @@ from ._configs.chromium_options import ChromiumOptions
 from ._configs.session_options import SessionOptions
 
 __all__ = ['ChromiumPage', 'ChromiumOptions', 'SessionOptions', 'SessionPage', 'WebPage', '__version__']
-__version__ = '4.0.4.6'
+__version__ = '4.0.4.7'
diff --git a/DrissionPage/_base/browser.py b/DrissionPage/_base/browser.py
index 018b84e..4ab366d 100644
--- a/DrissionPage/_base/browser.py
+++ b/DrissionPage/_base/browser.py
@@ -193,6 +193,7 @@ class Browser(object):
     def reconnect(self):
         """断开重连"""
         self._driver.stop()
+        BrowserDriver.BROWSERS.pop(self.id)
         self._driver = BrowserDriver(self.id, 'browser', self.address, self)
         self.run_cdp('Target.setDiscoverTargets', discover=True)
         self._driver.set_callback('Target.targetDestroyed', self._onTargetDestroyed)
diff --git a/DrissionPage/_base/driver.pyi b/DrissionPage/_base/driver.pyi
index a4810a2..329280b 100644
--- a/DrissionPage/_base/driver.pyi
+++ b/DrissionPage/_base/driver.pyi
@@ -71,6 +71,11 @@ class BrowserDriver(Driver):
 
     def __new__(cls, tab_id: str, tab_type: str, address: str, owner: Browser): ...
 
-    def __init__(self, tab_id: str, tab_type: str, address: str, owner: Browser): ...
+    def __init__(self, tab_id: str, tab_type: str, address: str, owner: Browser):
+        """
+
+        :rtype: object
+        """
+        ...
 
     def get(self, url) -> Response: ...
diff --git a/DrissionPage/_elements/chromium_element.py b/DrissionPage/_elements/chromium_element.py
index 9c11a49..6ba1317 100644
--- a/DrissionPage/_elements/chromium_element.py
+++ b/DrissionPage/_elements/chromium_element.py
@@ -1447,12 +1447,10 @@ def run_js(page_or_ele, script, as_expr, timeout, args=None):
     except TimeoutError:
         raise TimeoutError(f'执行js超时（等待{timeout}秒）。')
     except ContextLostError:
-        if is_page:
-            raise ContextLostError('页面已被刷新，请尝试等待页面加载完成再执行操作。')
-        else:
-            raise ElementLostError('原来获取到的元素对象已不在页面内。')
+        raise ContextLostError('页面已被刷新，请尝试等待页面加载完成再执行操作。') if is_page else ElementLostError(
+            '原来获取到的元素对象已不在页面内。')
 
-    if res is None and page.states.has_alert:
+    if not res:  # _timeout=0或js激活alert时
         return None
 
     exceptionDetails = res.get('exceptionDetails')
@@ -1463,7 +1461,7 @@ def run_js(page_or_ele, script, as_expr, timeout, args=None):
         return parse_js_result(page, page_or_ele, res.get('result'), end_time)
     except Exception:
         from DrissionPage import __version__
-        raise RuntimeError(f'\njs结果解析错误\n内容：{res.get("result")}\n版本：{__version__}\n'
+        raise RuntimeError(f'\njs结果解析错误\n版本：{__version__}\n内容：{res}\njs：{script}\n'
                            f'出现这个错误可能意味着程序有bug，请把错误信息和重现方法告知作者，谢谢。\n'
                            f'报告网站：https://gitee.com/g1879/DrissionPage/issues')
 
diff --git a/DrissionPage/_functions/browser.py b/DrissionPage/_functions/browser.py
index 5075945..a707c61 100644
--- a/DrissionPage/_functions/browser.py
+++ b/DrissionPage/_functions/browser.py
@@ -317,23 +317,24 @@ def get_chrome_path(ini_path):
 
     # -----------从注册表中获取--------------
     from winreg import OpenKey, EnumValue, CloseKey, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, KEY_READ
+    txt = r'SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\chrome.exe'
     try:
-        key = OpenKey(HKEY_CURRENT_USER,
-                      r'SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\chrome.exe',
-                      reserved=0, access=KEY_READ)
+        key = OpenKey(HKEY_CURRENT_USER, txt, reserved=0, access=KEY_READ)
         k = EnumValue(key, 0)
         CloseKey(key)
         if k[1]:
             return k[1]
-        key = OpenKey(HKEY_LOCAL_MACHINE,
-                      r'SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\chrome.exe',
-                      reserved=0, access=KEY_READ)
-        k = EnumValue(key, 0)
-        CloseKey(key)
-        return k[1]
 
-    except FileNotFoundError:
-        pass
+    except (FileNotFoundError, OSError):
+        try:
+            key = OpenKey(HKEY_LOCAL_MACHINE, txt, reserved=0, access=KEY_READ)
+            k = EnumValue(key, 0)
+            CloseKey(key)
+            if k[1]:
+                return k[1]
+
+        except (FileNotFoundError, OSError):
+            pass
 
     # -----------从系统变量中获取--------------
     for path in environ.get('PATH', '').split(';'):
diff --git a/DrissionPage/_units/downloader.py b/DrissionPage/_units/downloader.py
index 8f7f2b5..73dc956 100644
--- a/DrissionPage/_units/downloader.py
+++ b/DrissionPage/_units/downloader.py
@@ -31,13 +31,7 @@ class DownloadManager(object):
         self._flags = {}  # {tab_id: [bool, DownloadMission]}
 
         if self._page.download_path:
-            self._browser.driver.set_callback('Browser.downloadProgress', self._onDownloadProgress)
-            self._browser.driver.set_callback('Browser.downloadWillBegin', self._onDownloadWillBegin)
-            r = self._browser.run_cdp('Browser.setDownloadBehavior', downloadPath=self._page.download_path,
-                                      behavior='allowAndName', eventsEnabled=True)
-            if 'error' in r:
-                print('浏览器版本太低无法使用下载管理功能。')
-            self._running = True
+            self.set_path(self._page, self._page.download_path)
 
         else:
             self._running = False
diff --git a/DrissionPage/_units/waiter.py b/DrissionPage/_units/waiter.py
index 5398a1b..6450dec 100644
--- a/DrissionPage/_units/waiter.py
+++ b/DrissionPage/_units/waiter.py
@@ -18,12 +18,17 @@ class BaseWaiter(object):
         """
         self._driver = page_or_ele
 
-    def __call__(self, second):
-        """等待若干秒
+    def __call__(self, second, scope=None):
+        """等待若干秒，如传入两个参数，等待时间为这两个数间的一个随机数
         :param second: 秒数
+        :param scope: 随机数范围
         :return: None
         """
-        sleep(second)
+        if scope is None:
+            sleep(second)
+        else:
+            from random import uniform
+            sleep(uniform(second, scope))
 
     def ele_deleted(self, loc_or_ele, timeout=None, raise_err=None):
         """等待元素从DOM中删除
@@ -328,12 +333,17 @@ class ElementWaiter(object):
         self._page = page
         self._ele = ele
 
-    def __call__(self, second):
-        """等待若干秒
+    def __call__(self, second, scope=None):
+        """等待若干秒，如传入两个参数，等待时间为这两个数间的一个随机数
         :param second: 秒数
+        :param scope: 随机数范围
         :return: None
         """
-        sleep(second)
+        if scope is None:
+            sleep(second)
+        else:
+            from random import uniform
+            sleep(uniform(second, scope))
 
     def deleted(self, timeout=None, raise_err=None):
         """等待元素从dom删除
diff --git a/DrissionPage/_units/waiter.pyi b/DrissionPage/_units/waiter.pyi
index 92ed44b..300c176 100644
--- a/DrissionPage/_units/waiter.pyi
+++ b/DrissionPage/_units/waiter.pyi
@@ -18,7 +18,7 @@ class BaseWaiter(object):
     def __init__(self, page: ChromiumBase):
         self._driver: ChromiumBase = ...
 
-    def __call__(self, second: float) -> None: ...
+    def __call__(self, second: float, scope: float = None) -> None: ...
 
     def ele_deleted(self,
                     loc_or_ele: Union[str, tuple, ChromiumElement],
@@ -78,7 +78,7 @@ class ElementWaiter(object):
         self._ele: ChromiumElement = ...
         self._page: ChromiumBase = ...
 
-    def __call__(self, second: float) -> None: ...
+    def __call__(self, second: float, scope: float = None) -> None: ...
 
     def deleted(self, timeout: float = None, raise_err: bool = None) -> bool: ...