undefined method `*' for nil:NilClass

I have the following error when clicking run in explorer:

undefined method `*' for nil:NilClass

What does it mean? How do I debug this? 

this is my model: 

connection: "my_source_table"

# include all the views
include: "/views/*.view"

explore: daily_pages  {
  from: daily_pages
}

explore: +daily_pages {
  sql_always_where:
    1=1
    {% if daily_pages.current_vs_previous_period_advanced._in_query %}AND ${daily_pages.current_vs_previous_period_advanced} IS NOT NULL{% endif %}
    {% if parameters.apply_to_date_filter_advanced._is_filtered %}AND ${daily_pages.is_to_date_advanced}{% endif %}
   ;;

    join: parameters {}

  }
 

This is my view: 

view: daily_pages {
  sql_table_name: `bigquery-ga360-38002.73027846.ga_sessions_202301*`
    ;;

  dimension_group: date {
    type: time
    description: "date"
    group_label: "hit level row date"
    timeframes: [
      raw,
      date,
      week,
      month,
      quarter,
      month_num,
      year,
      day_of_week_index,
      hour_of_day,
      day_of_year,
      day_of_month,
      month_name,
      day_of_week
    ]
    convert_tz: no
    datatype: date
    sql: ${TABLE}.date ;;
  }

  dimension: visitNumber {
    type: number
    description: "number of visits"
    sql: ${TABLE}.visitNumber ;;
  }

  measure: sum_visitNumber {
    type: sum
    sql: ${visitNumber} ;;
  }
}

I also have other view files coming from the implementation of this guide https://blog.montrealanalytics.com/the-ultimate-guide-to-period-over-period-analysis-in-looker-f19358397f19

I have the error when I’m trying to run a query from the explorer only with the date field and the sum_visitNumber Measure.