IndexSizeError: The index is not in the allowed range.

[ros2-ship]

Describe the bug

To Reproduce

Expected behavior

Screenshots

Applicable Versions:

• Netlify CMS version: netlify-cms-app@2.15.20
• Git provider: github
• Browser version: Mozilla/5.0 (iPhone; CPU iPhone OS 14_4 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/91.0.4472.80 Mobile/15E148 Safari/604.1

CMS configuration

backend:
  name: github
  repo: netlify/netlify-cms
  squash_merges: true
  open_authoring: true
local_backend: true
site_url: https://www.netlifycms.org
publish_mode: editorial_workflow
media_folder: website/static/img
public_folder: /img
docs_collection:
  folder: website/content/docs
  create: true
  summary: "{{weight}} - {{title}}"
  preview_path: docs/{{slug}}
  sortable_fields:
    - weight
    - title
    - group
  fields:
    - label: Section
      name: group
      widget: relation
      collection: settings
      file: docs_sections
      search_fields:
        - menu.docs.*.name
        - menu.docs.*.title
      display_fields:
        - menu.docs.*.title
      value_field: menu.docs.*.name
    - label: Order
      name: weight
      widget: number
    - label: Title
      name: title
    - label: Body
      name: body
      widget: markdown
word_list:
  fields:
    - label: Extends
      name: extends
      widget: hidden
      default: existence
    - label: Output message
      name: message
      widget: string
    - label: Ignore Case
      name: ignorecase
      widget: boolean
      default: true
      required: false
    - label: Notification Level
      name: level
      widget: select
      default: suggestion
      options:
        - label: Suggestion
          value: suggestion
        - label: Warning
          value: warning
        - label: Error
          value: error
    - label: Entries
      name: tokens
      widget: list
collections:
  - label: Settings
    name: settings
    hide: true
    files:
      - label: Docs Sections
        name: docs_sections
        file: website/site.yml
        fields:
          - label: menu
            name: menu
            widget: object
            fields:
              - label: Sections
                label_singular: Section
                name: docs
                widget: list
                summary: "{{title}} ({{name}})"
                fields:
                  - label: Full Name
                    name: title
                    widget: string
                  - label: Summary Name
                    name: name
                    widget: string
    publish: true
    type: file_based_collection
    sortable_fields:
      - commit_date
      - commit_author
    view_filters: []
    view_groups: []
  - label: Style & Usage Options
    name: linter
    hide: false
    files:
      - fields:
          - label: Extends
            name: extends
            widget: hidden
            default: existence
          - label: Output message
            name: message
            widget: string
          - label: Ignore Case
            name: ignorecase
            widget: boolean
            default: true
            required: false
          - label: Notification Level
            name: level
            widget: select
            default: suggestion
            options:
              - label: Suggestion
                value: suggestion
              - label: Warning
                value: warning
              - label: Error
                value: error
          - label: Entries
            name: tokens
            widget: list
        label: Acronyms
        name: acronyms
        file: website/src/writing-guide/styles/Avoid/Acronyms.yml
      - fields:
          - label: Extends
            name: extends
            widget: hidden
            default: existence
          - label: Output message
            name: message
            widget: string
          - label: Ignore Case
            name: ignorecase
            widget: boolean
            default: true
            required: fa
...

[erezrokah]

Hi @ros2-ship, can you share a reproduction of the issue? See https://github.com/netlify/netlify-cms/issues/new?assignees=&labels=type%3A+bug&template=bug_report.md&title=Please+replace+with+a+clear+and+descriptive+title