刚注册百度bae。想弄个小测试，可是每次部署完了之后，第一次访问没问题，然后点链接或者重新载入就会出现500的错误了。
我在本地怎么刷新都不会出错的，下面是贴的错误信息
Execute 'application' failed
Traceback (most recent call last):
File "/home/admin/runtime/modules/bae/core/wsgi.py", line 72, in __call__
return self.app(environ, start_response)
File "/home/bae/app/deps/flask/app.py", line 1836, in __call__
return self.wsgi_app(environ, start_response)
File "/home/bae/app/deps/flask/app.py", line 1820, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/home/bae/app/deps/flask/app.py", line 1403, in handle_exception
reraise(exc_type, exc_value, tb)
File "/home/bae/app/deps/flask/app.py", line 1817, in wsgi_app
response = self.full_dispatch_request()
File "/home/bae/app/deps/flask/app.py", line 1477, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/home/bae/app/deps/flask/app.py", line 1381, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/home/bae/app/deps/flask/app.py", line 1475, in full_dispatch_request
rv = self.dispatch_request()
File "/home/bae/app/deps/flask/app.py", line 1461, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/home/bae/app/blog/views.py", line 26, in index
posts=posts)
File "/home/bae/app/deps/flask/templating.py", line 128, in render_template
context, ctx.app)
File "/home/bae/app/deps/flask/templating.py", line 110, in _render
rv = template.render(context)
File "/home/bae/app/deps/jinja2/environment.py", line 969, in render
return self.environment.handle_exception(exc_info, True)
File "/home/bae/app/deps/jinja2/environment.py", line 742, in handle_exception
reraise(exc_type, exc_value, tb)
File "/home/bae/app/blog/templates/index.html", line 8, in top-level template code
<h1>Hi, {{user.nickname}}!</h1>
File "/home/bae/app/deps/markupsafe/__init__.py", line 69, in __new__
if hasattr(base, '__html__'):
TypeError: 'NoneType' object is not callable