Error: view_name.field_name no longer exists on explore_name and will be ignored

After you run an Explore or a Look, you might occasionally see the following warning:

⚠️ view_name.field_name no longer exists on explore_name and will be ignored.

This warning indicates that fields that you had previously selected or saved in an Explore or a Look are now no longer available. There are several potential causes for this occurrence:

The field or fields that are referenced in the warning exist only in Development Mode, and you're viewing the Explore or Look in Production Mode (or vice versa).
A join was removed from the explore file's LookML definition, which removed the field that is referenced in the warning.

For example, if you see the warning users.name no longer exists on Companies, and will be ignored, this may indicate that the users view and its fields are no longer joined to the companies Explore and are therefore unavailable in the Look or Explore.

You can use the metadata panel in the IDE to see all explore definitions that reference a specific view.
A change was made to the view's name in its file, or the view reference in the explore LookML definition was changed with a parameter such as view_name.

For example, an underlying view for an Explore called users was updated with a view_name parameter that references a view called customers:
```
        explore: users {
            view_name: customers
        }
    
```

Resolving the warning if fields that are referenced in the warning were deleted intentionally

If a field that is referenced in a warning was intentionally removed by a LookML developer, follow these steps to resolve the warning for either a Look or an Explore.

Resolving the warning for a Look

To resolve the view_name.field_name no longer exists on explore_name and will be ignored warning for a Look:

Select the Edit button in the top right corner to edit the Look.
Once in edit mode, select the x next to each error message to clear the warning.
Make a change, such as adding any field from the field picker and then removing it, to activate the Save button.
Select Save.

This will update and save the Look to omit the deleted field or fields and the accompanying errors.

Resolving the warning for an Explore

To resolve the view_name.field_name no longer exists on explore_name and will be ignored warning for an Explore:

Make a change, such as adding any field from the field picker and then removing it.
Select Run to rerun the Explore query.