I'm running into errors with parameters being passed into a mapped task.

@task(name="Update a tables partition")
def update_partitions(table, task_start_date=None, task_end_date=None):
    # print(task_start_date)
    # print(task_end_date)
    print(table)

with Flow(name="demo", on_failure=datadog_notifier) as flow:
    start_date = Parameter('task_start_date', required=False)
    end_date = Parameter('task_end_date', required=False)

    tables_to_create = get_uncreated_tables()
    tables_already_created = get_created_tables()
    create_table.map(tables_to_create)
    # tables to create will have created
    update_partitions.map(tables_to_create + tables_already_created, task_start_date=start_date, task_end_date=end_date)

Other tasks removed for clarity, but they return a list of objects. Results in an error:

[2020-07-21 12:36:43] INFO - prefect.TaskRunner | Task 'Update a tables partition': Starting task run...
[2020-07-21 12:36:43] DEBUG - prefect.TaskRunner | Task 'Update a tables partition': Handling state change from Pending to Failed
[2020-07-21 12:36:43] INFO - prefect.TaskRunner | Task 'Update a tables partition': finished task run for task with final state: 'Failed'
[2020-07-21 12:36:43] INFO - prefect.FlowRunner | Flow run FAILED: some reference tasks failed.
[2020-07-21 12:36:43] DEBUG - prefect.FlowRunner | Flow 'demo': Handling state change from Running to Failed

Removing the parameters runs everything fine.

Found the answer, needed to set the parameters as unmapped.