Currently, any error in migration handlers has effect to generatee a 500 error code as migration end point return.
We could add a try...catch... in ConfigurationTypeResourceImpl to support ComponentException and so return better understandable code : https://github.com/Talend/component-runtime/blob/9756a37251ef5ee731e353e7d111caca7e720bfa/component-server-parent/component-server/src/main/java/org/talend/sdk/component/server/front/ActionResourceImpl.java#L152