LookML error: The field "fieldnamehere" is of type "string" but is listening to a filter of type "field_filter" that specifies a field of type "(?)"

[rvsubman]

Hi, 

I am getting this warning when I validate in LookML. I have a filter for currency (filter name: Currency).

What is confusing is that there are several fields that listen to this filter, but only some fields have this warning. Moreover, all the fields that have a warning are all in the same model. The LookML dashboard is also in the same model. 

This is what one of element looks like (the errors shows up for all elements where there is a ‘listen’ to the ‘Currency’ filter. The script for filter is also given below.

element parameters..

listen:
      Reconciliation Date: view1.field1
      Currency: cash_advance_balances_daily.currency

.

.

.

filters:
  - name: Reconciliation Date
    .

    . 
  - name: Currency
    title: Currency
    type: field_filter
    model: core
    explore: multi_currency_conversion_batches
    field: fx_conversion_orders_request.source_currency. #this is of string type 
    default_value: 'EUR'
    allow_multiple_values: true
    required: true
    ui_config:
      type: dropdown_menu
      display: inline
      options: 
      - EUR