Construction/initialization of custom filter instance, configured in undertow subsystem uses incorrect/undefined TCCL --------------------------------------------------------------------------------------------------------------------- Key: WFLY-9773 URL: https://issues.jboss.org/browse/WFLY-9773 Project: WildFly Issue Type: Bug Components: Web (Undertow) Affects Versions: 10.1.0.Final, 11.0.0.Final Environment: Windows 10 Java 1.8.0_112 WildFly 10.1.Final Reporter: Thomas Isaksen Assignee: Stuart Douglas Attachments: IgniteHandler.zip, gatekeeper-token-config.xml.zip Custom module class loading fails with ClassNotFoundException I have attached a reproducible example here but it is also available on the forum thread mentioned.