我在气流服务器中执行airflow trigger_dag cng-hello_world命令，导致以下错误。请提出建议。
我点击了以下链接：-http://michal.karzynski.pl/blog/2017/03/19/developing-workflows-with-apache-airflow/
通过气流UI执行相同的Dag
[2019-02-06 11:57:41,755] {settings.py:174} INFO - setting.configure_orm(): Using pool settings. pool_size=5, pool_recycle=2000
[2019-02-06 11:57:43,326] {plugins_manager.py:97} ERROR - invalid syntax (airflow_api.py, line 7)
Traceback (most recent call last):
File "/usr/lib/python2.7/site-packages/airflow/plugins_manager.py", line 86, in <module>
m = imp.load_source(namespace, filepath)
File "/home/ec2-user/airflow/plugins/airflow_api.py", line 7
<!DOCTYPE html>
^
SyntaxError: invalid syntax
[2019-02-06 11:57:43,326] {plugins_manager.py:98} ERROR - Failed to import plugin /home/ec2-user/airflow/plugins/airflow_api.py
[2019-02-06 11:57:43,326] {plugins_manager.py:97} ERROR - invalid syntax (__init__.py, line 7)
Traceback (most recent call last):
File "/usr/lib/python2.7/site-packages/airflow/plugins_manager.py", line 86, in <module>
m = imp.load_source(namespace, filepath)
File "/home/ec2-user/airflow/plugins/__init__.py", line 7
<!DOCTYPE html>
^
SyntaxError: invalid syntax
[2019-02-06 11:57:43,327] {plugins_manager.py:98} ERROR - Failed to import plugin /home/ec2-user/airflow/plugins/__init__.py
[2019-02-06 11:57:47,236] {__init__.py:51} INFO - Using executor CeleryExecutor
[2019-02-06 11:57:48,420] {models.py:258} INFO - Filling up the DagBag from /home/ec2-user/airflow/dags
[2019-02-06 11:57:48,783] {cli.py:237} INFO - Created <DagRun cng-hello_world @ 2019-02-06 11:57:48+00:00: manual__2019-02-06T11:57:48+00:00, externally triggered: True>