Error with comments when using $ref: ExampleElement value and externalValue fields are mutually exclusive.

Q&A (please complete the following information)

• OS: Debian 12
• Browser: Chrome
• Version: 133
• Method of installation: dist folder
• Swagger-UI version: 5.20.8
• Swagger/OpenAPI version: OpenAPI 3.1.0

Content & configuration

index.yaml

openapi: 3.1.0
info:
  title: 'Bug test'
  version: 1.0.0

servers:
  - url: /bug

paths:
  /test:
    $ref: test.yaml

test.yaml:

post:
  responses:
    '200':
      content:
        application/json:
          examples:
            testExample:
              summary: Test example
              externalValue: test.json

test.json:

{}

Describe the bug you're encountering

This configuration with $ref used in path is throwing Error:

Resolver error at post.responses.200.content.application/json.examples.testExample.externalValue
Could not resolve reference: ExampleElement value and externalValue fields are mutually exclusive.

When there is no $ref used and the content of test.yaml is directly included in the main index.yaml, no error occurs.

To reproduce...

Just open this definition in UI.

Expected behavior

This error should not occur as the definition is exactly the same. The difference is just the $ref. The $ref is supported under particular paths in OpenAPI 3.

Start by opening the supplied index.yaml in Swagger UI with test.yaml and test.json available, then compare it with the inline definition described in the report. Trace the $ref path to the externalValue example and verify that the referenced configuration no longer raises the mutually exclusive fields error while preserving the expected example behavior.