In the Workstation when creating a VS image from swagger, that has a $ref definition that refers to another $ref definition, it fails with:
java.lang.NullPointerException
at com.itko.lisa.vse.swagger.helper.SwaggerSchemaResolver$ReferenceResolverImpl.resolve
Service Virtualization 10.7.2
Open a support case to request patch_DE604223_10.7.2_GA.jar