[ https://issues.jboss.org/browse/WFLY-6097?page=com.atlassian.jira.plugin.... ] Renann Prado updated WFLY-6097: ------------------------------- Description: 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} was: 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} -- This message was sent by Atlassian JIRA (v6.4.11#64026)