### Discussed in https://github.com/apache/airflow/discussions/19366

<div type='discussions-op-text'>

<sup>Originally posted by **a-pertsev** November  2, 2021</sup>
### Apache Airflow version

2.2.1 (latest released)

### Operating System

Ubuntu 20.04 LTS

### Versions of Apache Airflow Providers

apache-airflow-providers-amazon==2.3.0
apache-airflow-providers-apache-cassandra==2.1.0
apache-airflow-providers-ftp==2.0.1
apache-airflow-providers-google==6.0.0
apache-airflow-providers-http==2.0.1
apache-airflow-providers-imap==2.0.1
apache-airflow-providers-jdbc==2.0.1
apache-airflow-providers-mysql==2.1.1
apache-airflow-providers-postgres==2.3.0
apache-airflow-providers-presto==2.0.1
apache-airflow-providers-slack==4.1.0
apache-airflow-providers-sqlite==2.0.1

### Deployment

Virtualenv installation

### Deployment details

_No response_

### What happened

Got error when manually run newly created task in already finished dag run (in UI).

### What you expected to happen

"Run" button should work without exceptions.

### How to reproduce

1. Define a dag with some tasks.
2. Create dag run (manually or by schedule)
3. Add new task into dag, deploy code
4. Select new task in UI and press "Run" button

### Anything else

_No response_

### Are you willing to submit PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)
</div>
airflow/www/views.py
current_dags = paused_dags
                num_of_all_dags = status_count_paused
            else:
                current_dags = all_dags
                num_of_all_dags = all_dags_count
            dags = (
                current_dags.order_by(DagModel.dag_id)
                .options(joinedload(DagModel.tags))
                .offset(start)
                .limit(dags_per_page)
                .all()
            )
            user_permissions = current_app.appbuilder.sm.get_current_user_permissions()
            all_dags_editable = (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG) in user_permissions
            can_create_dag_run = (
                permissions.ACTION_CAN_CREATE,
                permissions.RESOURCE_DAG_RUN,
            ) in user_permissions
            can_delete_dag = (
                permissions.ACTION_CAN_DELETE,
                permissions.RESOURCE_DAG,
            ) in user_permissions
            for dag in dags:
                if all_dags_editable:
                    dag.can_edit = True
                else:
                    dag_resource_name = permissions.RESOURCE_DAG_PREFIX + dag.dag_id
                    dag.can_edit = (permissions.ACTION_CAN_EDIT, dag_resource_name) in user_permissions
                dag.can_trigger = dag.can_edit and can_create_dag_run
                dag.can_delete = can_delete_dag