quarkusio/quarkus · error · IllegalArgumentException

The provided <settingName> setting value [<settingValue>] is

Error message

The provided <settingName> setting value [<settingValue>] is not supported!

What it means

loadSettingInstance expects the setting value to be either a Class object or a String containing a class name. If the configured value is neither (e.g. an instance of some other type, or a bare name that is not meant to be a class), the builder rejects it with this IllegalArgumentException naming the setting and the offending value.

Source

Thrown at extensions/hibernate-orm/runtime/src/main/java/io/quarkus/hibernate/orm/runtime/boot/FastBootMetadataBuilder.java:697

        if (clazz.isAssignableFrom(settingValue.getClass())) {
            instance = (T) settingValue;
        } else if (settingValue instanceof Class) {
            instanceClass = (Class<? extends T>) settingValue;
        } else if (settingValue instanceof String) {
            String settingStringValue = (String) settingValue;
            if (standardServiceRegistry != null) {
                final ClassLoaderService classLoaderService = standardServiceRegistry.getService(ClassLoaderService.class);

                instanceClass = classLoaderService.classForName(settingStringValue);
            } else {
                try {
                    instanceClass = (Class<? extends T>) Class.forName(settingStringValue);
                } catch (ClassNotFoundException e) {
                    throw new IllegalArgumentException("Can't load class: " + settingStringValue, e);
                }
            }
        } else {
            throw new IllegalArgumentException(
                    "The provided " + settingName + " setting value [" + settingValue + "] is not supported!");
        }

        if (instanceClass != null) {
            try {
                instance = instanceClass.getConstructor().newInstance();
            } catch (InstantiationException | IllegalAccessException | NoSuchMethodException | InvocationTargetException e) {
                throw new IllegalArgumentException(
                        "The " + clazz.getSimpleName() + " class [" + instanceClass + "] could not be instantiated!",
                        e);
            }
        }

        return instance;
    }

}

View on GitHub (pinned to e1c734241f)

Solutions

1. Supply the value as a String containing the fully-qualified class name (or the Class itself), not an instance.
2. Inspect the message's settingName/value to find which property holds the wrong type.
3. Remove the property if an equivalent Quarkus-first configuration option exists (e.g. quarkus.hibernate.orm.metadata-builder-contributor).

Example fix

// before
properties.put(AvailableSettings.SESSION_FACTORY_NAME, myNamingStrategyInstance); // wrong slot/type
// after
properties.put(AvailableSettings.PHYSICAL_NAMING_STRATEGY, "com.example.MyPhysicalNamingStrategy");

Object v = properties.get(settingName);
if (v != null && !(v instanceof String) && !(v instanceof Class)) {
    throw new IllegalArgumentException(settingName + " must be a class name String or Class, got " + v.getClass());
}

try {
    bootPersistenceUnit();
} catch (IllegalArgumentException e) {
    if (e.getMessage().contains("is not supported")) {
        log.error("Setting value has wrong type; provide a class name string");
    }
}

When it happens

Trigger: Passing a non-Class/non-String object into a setting like hibernate.metadata_builder_contributor (or its Quarkus equivalents) — e.g. programmatically setting an instance, a lambda, or a wrong type via a custom properties map fed to FastBootMetadataBuilder.

Common situations: Building the persistence unit properties programmatically and putting an instance object instead of the class; config binding mapping the property to a non-String type; copying plain-Hibernate settings that accept instances into the Quarkus static-init bootstrap which only accepts class names.

Related errors

• Top command must implement org.aesh.command.Command interfac
• The Hibernate ORM configuration in Quarkus does not support
• Datasource must be defined for persistence unit '%s'. Settin
• Unable to find file referenced in '<puPropertyKey(persistenc
• The FastbootHibernateProvider PersistenceProvider can not su

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/2e64e14824899f43. Report an issue: GitHub.