Dag load is failing due to Internal server error

[Huthesh]

I have two DAGs, sample_dag and trigger-dag-example.
trigger-dag-example example triggers sample_dag.

sample-dag.txt
trigger-dag-example.txt

When I run trigger-dag-example, I cannot access the UI. I am getting 500 internal error
Webserver has following log

webserver | File "/usr/local/lib/python3.9/site-packages/flask_appbuilder/templates/appbuilder/baselayout.html", line 39, in block_body webserver | File "/usr/local/lib/python3.9/site-packages/airflow/www/templates/airflow/main.html", line 178, in block_messages webserver | File "/usr/local/lib/python3.9/site-packages/jinja2/runtime.py", line 303, in call webserver | return __obj(*args, **kwargs) webserver | File "/usr/local/lib/python3.9/site-packages/jinja2/runtime.py", line 768, in __call__ webserver | return self._invoke(arguments, autoescape) webserver | File "/usr/local/lib/python3.9/site-packages/jinja2/runtime.py", line 782, in _invoke webserver | rv = self._func(*arguments) webserver | File "/usr/local/lib/python3.9/site-packages/airflow/www/templates/airflow/_messages.html", line 40, in macro webserver | File "/usr/local/lib/python3.9/site-packages/jinja2/runtime.py", line 303, in call webserver | return __obj(*args, **kwargs) webserver | File "/usr/local/lib/python3.9/site-packages/jinja2/runtime.py", line 768, in __call__ webserver | return self._invoke(arguments, autoescape) webserver | File "/usr/local/lib/python3.9/site-packages/jinja2/runtime.py", line 782, in _invoke webserver | rv = self._func(*arguments) webserver | File "/usr/local/lib/python3.9/site-packages/airflow/www/templates/airflow/main.html", line 170, in macro webserver | File "/usr/local/lib/python3.9/site-packages/jinja2/runtime.py", line 303, in call webserver | return __obj(*args, **kwargs) webserver | File "/usr/local/lib/python3.9/site-packages/airflow/macros/__init__.py", line 91, in datetime_diff_for_humans webserver | return pendulum.instance(dt).diff_for_humans(since) webserver | File "/usr/local/lib64/python3.9/site-packages/pendulum/datetime.py", line 746, in diff_for_humans webserver | diff = self.diff(other) webserver | File "/usr/local/lib64/python3.9/site-packages/pendulum/datetime.py", line 714, in diff webserver | return Interval(self, dt, absolute=abs) webserver | File "/usr/local/lib64/python3.9/site-packages/pendulum/interval.py", line 199, in __init__ webserver | self._delta: PreciseDiff = precise_diff(_start, _end) webserver | pyo3_runtime.PanicException: called Result::unwrap()on anErr value: PyDowncastError { from: None, to: "PyString" } webserver | 172.17.0.1 - - [01/Aug/2024:14:20:55 +0000] "GET /dags/trigger-dag-example/grid HTTP/1.1" 500 0 "-" "-"

Environment

Mysql:8
Airflow 2.9.2
Running in Linux container

[Huthesh]

issue was due to using sequential executor. Issue was fixed by moving to localexecutor.
There seems to be web server issue when using sequential executor and triggering another dag