Tomcat 8.5.5 that was released last month doesn't work with the KC Tomcat Adapter. This is because of this bug that has been fixed on their side : https://bz.apache.org/bugzilla/show_bug.cgi?id=59823 and their pretty "breaking-change" fix : https://github.com/apache/tomcat85/commit/c74595783a821cf43de45def094254 c673298e73?diff=split I created a ticket , https://issues.jboss.org/browse/KEYCLOAK-3669 , that describes the problem and the possible fix. But the question is : this fix will only be valid (and possible to compile) for version of Tomcat > 8.5.5 (including 9). Does that mean we need to create a new Adapter just for this version ? I'm not sure there is another solution. Sebi ps : This also affects people using the latest version of Springboot, as it uses tomcat 8.5.5 _______________________________________________ keycloak-dev mailing list keycloak-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/keycloak-dev