Error response handling from bean validation ignores Accept header ------------------------------------------------------------------ Key: WFLY-6097 URL: https://issues.jboss.org/browse/WFLY-6097 Project: WildFly Issue Type: Bug Components: REST Affects Versions: 10.0.0.Final Environment: Mac OS X El Captain java version "1.8.0_66" Java(TM) SE Runtime Environment (build 1.8.0_66-b17) Java HotSpot(TM) 64-Bit Server VM (build 25.66-b17, mixed mode) Reporter: Renann Prado Assignee: Weinan Li Attachments: delivery-optimization-ear-1.0.Final.ear Basically I have a very simple application that has request validation in the REST endpoints. According to the documentation of RESTEasy, I should get a JSON error response if I put "application/json" in Accept header in the request. https://docs.jboss.org/resteasy/docs/3.0.13.Final/userguide/html/Validati... The mentioned feature worked just fine in Wildfly 9.0.2.Final. Now, however, it doesn't. I have tried to upgrade the dependencies in the pom.xml to use dependencies from Wildfly 10.0.0.Final, but still no luck. Though the attached application deploys just fine in Wildfly 9.0.2.Final and Wildfly 10.0.0.Final. In WF 9.0.2.Final I used to get the below error *JSON* {code:json} { "exception": null, "fieldViolations": [], "propertyViolations": [], "classViolations": [], "parameterViolations": [{ "constraintType": "PARAMETER", "path": "registerLogisticsNetwork.arg0.name", "message": "may not be null", "value": "" }], "returnValueViolations": [] } {code} In WF 10.0.0.Final I get this: {code} [PARAMETER] [registerLogisticsNetwork.arg0.name] [may not be null] [] {code}