## Bug description
I added an event (that exists) to an action, and now my action hangs forever.

I added an insight viewed event

w/ filters `insight == RETENTION` and `same_retention_and_cohortizing_event = false` – this appears to have broken my action where it does not load and I cannot edit it.

Cannot reproduce this same behavior locally.


## Expected behavior
- The action loads if the schema is correct.
-  If there's erroneous data it should load and let me edit it.

## How to reproduce

1. Create an action on Posthog cloud, in our main app
2. Add 'insight viewed' with filters `insight == RETENTION` and `same_retention_and_cohortizing_event = false`
3. The action will spin forever

## Environment

- [x] PostHog Cloud
- [ ] self-hosted PostHog, version/commit: _please provide_

## Additional context

[Sentry error](https://sentry.io/organizations/posthog/issues/2378948964/?project=1899813&referrer=slack)

Console errors 
<img width="1607" alt="Screen Shot 2021-05-03 at 5 45 39 PM" src="https://user-images.githubusercontent.com/5965891/116950024-b0d7a280-ac38-11eb-93c8-245390240532.png">
<img width="1167" alt="Screen Shot 2021-05-03 at 5 51 34 PM" src="https://user-images.githubusercontent.com/5965891/116950026-b208cf80-ac38-11eb-96e1-6a8f018f650a.png">



#### *Thank you* for your bug report – we love squashing them!

ee/clickhouse/views/actions.py
content_sql, params = _process_content_sql(team, entity, filter)
    people = sync_execute(
        (PEOPLE_SQL if entity.math in [WEEKLY_ACTIVE, MONTHLY_ACTIVE] else PEOPLE_THROUGH_DISTINCT_SQL).format(
            content_sql=content_sql,
            latest_person_sql=GET_LATEST_PERSON_SQL.format(query=""),
            latest_distinct_id_sql=GET_LATEST_PERSON_DISTINCT_ID_SQL,
        ),
        params,
    )
    serialized_people = ClickhousePersonSerializer(people, many=True).data
    return serialized_people
def insert_entity_people_into_cohort(cohort: Cohort, entity: Entity, filter: Filter):
    content_sql, params = _process_content_sql(cohort.team, entity, filter)
    sync_execute(
        INSERT_COHORT_ALL_PEOPLE_THROUGH_DISTINCT_SQL.format(
            cohort_table=PERSON_STATIC_COHORT_TABLE,
            content_sql=content_sql,
            latest_person_sql=GET_LATEST_PERSON_SQL.format(query=""),
            latest_distinct_id_sql=GET_LATEST_PERSON_DISTINCT_ID_SQL,
        ),
        {"cohort_id": cohort.pk, "_timestamp": datetime.now(), **params},
    )
class LegacyClickhouseActionsViewSet(ClickhouseActionsViewSet):
    legacy_team_compatibility = True