## 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/models/property.py
)
            if is_person_query:
                final.append(filter_query)
                params.update(filter_params)
            else:
                final.append(
                    "AND {table_name}distinct_id IN ({filter_query})".format(
                        filter_query=GET_DISTINCT_IDS_BY_PROPERTY_SQL.format(
                            filters=filter_query, latest_distinct_id_sql=GET_LATEST_PERSON_DISTINCT_ID_SQL
                        ),
                        table_name=table_name,
                    )
                )
                params.update(filter_params)
        elif prop.type == "element":
            query, filter_params = filter_element({prop.key: prop.value}, prepend="{}_".format(idx))
            final.append("AND {}".format(query[0]))
            params.update(filter_params)
        else:
            filter_query, filter_params = prop_filter_json_extract(
                prop,
                idx,
                prepend,
                prop_var="{}properties".format(table_name),
                allow_denormalized_props=allow_denormalized_props,
            )
            final.append(f"{filter_query} AND {table_name}team_id = %(team_id)s" if team_id else filter_query)
            params.update(filter_params)
    return " ".join(final), params
def prop_filter_json_extract(