NullpointerException and missing model object while using external schemas

I am trying to generate api and model object for my Open API specification using swagger code gen plugin ( v 3.0.24 )

I have the external schema reference for one of the response object ( refer yaml below )
I have the following plugin in my pom.xml

<plugin>
				<groupId>io.swagger.codegen.v3</groupId>
				<artifactId>swagger-codegen-maven-plugin</artifactId>
				<version>3.0.24</version>
				<executions>
					<execution>
						<goals>
							<goal>generate</goal>
						</goals>
						
						<configuration>
							<environmentVariables>
							<io.swagger.v3.parser.util.RemoteUrl.trustAll>true</io.swagger.v3.parser.util.RemoteUrl.trustAll>
							</environmentVariables>
			                <inputSpec>src/main/openapi/openapi.yaml</inputSpec>
			                <language>spring</language>
			                <templateDirectory>${basedir}/src/main/resources/templates</templateDirectory>
			                <output>${project.build.directory}/generated-sources</output>
			                <apiPackage>com.mydomain.api</apiPackage>
							<modelPackage>com.mydomain.model</modelPackage>
							<generateApiDocumentation>false</generateApiDocumentation>
							<generateModelDocumentation>false</generateModelDocumentation>
							<generateSupportingFiles>false</generateSupportingFiles>
							<generateApiTests>false</generateApiTests>
							<generateModelTests>false</generateModelTests>
							<configOptions>
								<dateLibrary>java8</dateLibrary>
								<interfaceOnly>true</interfaceOnly>
							</configOptions>
			            </configuration>
					</execution>
				</executions>
			</plugin>

I am getting the following exception. Also ErrorResponse model is not getting generated. Please advise

[WARNING] Exception while resolving:
java.lang.NullPointerException
	at io.swagger.v3.parser.util.OpenAPIDeserializer.getSchema(OpenAPIDeserializer.java:2450)
	at io.swagger.v3.parser.ResolverCache.loadRef(ResolverCache.java:152)
	at io.swagger.v3.parser.processors.ExternalRefProcessor.processRefToExternalSchema(ExternalRefProcessor.java:56)
	at io.swagger.v3.parser.processors.SchemaProcessor.processReferenceSchema(SchemaProcessor.java:214)
	at io.swagger.v3.parser.processors.SchemaProcessor.processSchema(SchemaProcessor.java:37)
	at io.swagger.v3.parser.processors.ResponseProcessor.processResponse(ResponseProcessor.java:52)
	at io.swagger.v3.parser.processors.OperationProcessor.processOperation(OperationProcessor.java:67)
	at io.swagger.v3.parser.processors.PathsProcessor.processPaths(PathsProcessor.java:84)
	at io.swagger.v3.parser.OpenAPIResolver.resolve(OpenAPIResolver.java:49)
	at io.swagger.v3.parser.OpenAPIV3Parser.resolve(OpenAPIV3Parser.java:175)
	at io.swagger.v3.parser.OpenAPIV3Parser.readContents(OpenAPIV3Parser.java:154)
	at io.swagger.v3.parser.OpenAPIV3Parser.readLocation(OpenAPIV3Parser.java:89)
	at io.swagger.parser.OpenAPIParser.readLocation(OpenAPIParser.java:16)
	at io.swagger.codegen.v3.config.CodegenConfigurator.toClientOptInput(CodegenConfigurator.java:517)
	at io.swagger.codegen.v3.maven.plugin.CodeGenMojo.execute_(CodeGenMojo.java:532)

Swagger-codegen version

3.0.24

Swagger declaration file content or url

 responses:
        "500":
          description: Error response
          content:
            application/json:
              schema: 
                $ref: 'https://swaggerhub.mydomain.com/v1/domains/Global_Domains/V0/#/responses/ErrorResponse'

Command line used for generation

Steps to reproduce

Related issues/PRs

Suggest a fix/enhancement

Start with OpenAPIDeserializer.java:2450 and trace the external reference through ResolverCache.java, ExternalRefProcessor.java, and SchemaProcessor.java. Reproduce the Maven generation using the shown external $ref and confirm that resolution no longer raises a NullPointerException and that the ErrorResponse model is generated.