[Bug]:Codegen in 3.0.78 fails with JsonParseException: Unrecognized token 'openapi':

[195858]

Description

Codegen failing with exception:

[main] ERROR io.swagger.parser.SwaggerCompatConverter - failed to read resource listing
com.fasterxml.jackson.core.JsonParseException: Unrecognized token 'openapi': was expecting (JSON String, Number, Array, Object or token 'null', 'true' or 'false')

This worked prior to 3.0.78

Swagger Codegen Version

3.0.78

Language / Generator

java

OpenAPI/Swagger Spec

I can not determine what is the relevant part of the api spec. It passes validation, e.g. in swagger editor

See - https://gist.github.com/195858/44676d1bf4dbc0b74183258df67c502f

Related Issues / Repos

Environment

• OS: Ubuntu/github action, MacOs
• Java Version: odk 25
• Build Tool:CLI
• Swagger Codegen CLI version: 3.0.78 (installed via brew install swagger-codegen_

Additional Context

Checklist

• I have searched the existing issues to make sure this is not a duplicate.
• I have included a minimal and reproducible spec example.
• [ x I have explained how to reproduce the issue.
• I have specified which generator/language is affected.