Multi AI Agent Systems with crewAI: L5 not working local

I’ve moved to a python project L5. I got this error. To solve it I’ve to use only one aync task. How can I use more than one async task?

Traceback (most recent call last):
File “/home/roby73/Documents/dev/python/udemy_course_lc_003/L4-crewAI-course-deeplearning.ai/main.py”, line 145, in
main()
File “/home/roby73/Documents/dev/python/udemy_course_lc_003/L4-crewAI-course-deeplearning.ai/main.py”, line 113, in main
event_management_crew = Crew(
^^^^^
File “/home/roby73/.local/share/virtualenvs/L4-crewAI-course-deeplearning.ai-nK5USIRW/lib/python3.11/site-packages/pydantic/main.py”, line 214, in init
validated_self = self.pydantic_validator.validate_python(data, self_instance=self)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
pydantic_core._pydantic_core.ValidationError: 1 validation error for Crew
The crew must end with at most one asynchronous task. [type=async_task_count, input_value={‘agents’: [Agent(role=Ve…own.)], ‘verbose’: True}, input_type=dict]

Process finished with exit code 1