Elytron, unable to configure Kerberos authentication in DR14

[standalone@localhost:9990 /] /subsystem=elytron/kerberos-security-factory=a:add(principal=HTTP/localhost@JBOSS.ORG, path=/somewhere, mechanism-oids=["1.2.840.113554.1.2.2","1.3.6.1.5.5.2"])
{
    "outcome" => "failed",
    "failure-description" => "WFLYCTL0158: Operation handler failed: java.lang.IllegalArgumentException",
    "rolled-back" => true
}

15:00:53,476 ERROR [org.jboss.as.controller.management-operation] (management-handler-thread - 4) WFLYCTL0013: Operation ("add") failed - address: ([
    ("subsystem" => "elytron"),
    ("kerberos-security-factory" => "a")
]): java.lang.IllegalArgumentException
	at org.jboss.dmr.ModelValue.asPropertyList(ModelValue.java:103)
	at org.jboss.dmr.ModelNode.asPropertyList(ModelNode.java:503)
	at org.wildfly.extension.elytron.KerberosSecurityFactoryDefinition$2.getValueSupplier(KerberosSecurityFactoryDefinition.java:168)
	at org.wildfly.extension.elytron.TrivialAddHandler.performRuntime(TrivialAddHandler.java:77)
	at org.jboss.as.controller.AbstractAddStepHandler$1.execute(AbstractAddStepHandler.java:151)
	at org.jboss.as.controller.AbstractOperationContext.executeStep(AbstractOperationContext.java:979)
	at org.jboss.as.controller.AbstractOperationContext.processStages(AbstractOperationContext.java:722)
	at org.jboss.as.controller.AbstractOperationContext.executeOperation(AbstractOperationContext.java:441)
	at org.jboss.as.controller.OperationContextImpl.executeOperation(OperationContextImpl.java:1388)
	at org.jboss.as.controller.ModelControllerImpl.internalExecute(ModelControllerImpl.java:421)
	at org.jboss.as.controller.ModelControllerImpl.lambda$execute$1(ModelControllerImpl.java:243)
	at org.wildfly.security.auth.server.SecurityIdentity.runAs(SecurityIdentity.java:263)
	at org.wildfly.security.auth.server.SecurityIdentity.runAs(SecurityIdentity.java:229)
	at org.jboss.as.controller.ModelControllerImpl.execute(ModelControllerImpl.java:243)
	at org.jboss.as.controller.remote.ModelControllerClientOperationHandler$ExecuteRequestHandler.doExecute(ModelControllerClientOperationHandler.java:217)
	at org.jboss.as.controller.remote.ModelControllerClientOperationHandler$ExecuteRequestHandler.access$400(ModelControllerClientOperationHandler.java:137)
	at org.jboss.as.controller.remote.ModelControllerClientOperationHandler$ExecuteRequestHandler$1$1.run(ModelControllerClientOperationHandler.java:161)
	at org.jboss.as.controller.remote.ModelControllerClientOperationHandler$ExecuteRequestHandler$1$1.run(ModelControllerClientOperationHandler.java:157)
	at org.wildfly.security.auth.server.SecurityIdentity.runAs(SecurityIdentity.java:287)
	at org.wildfly.security.auth.server.SecurityIdentity.runAs(SecurityIdentity.java:244)
	at org.jboss.as.controller.AccessAuditContext.doAs(AccessAuditContext.java:254)
	at org.jboss.as.controller.AccessAuditContext.doAs(AccessAuditContext.java:225)
	at org.jboss.as.controller.remote.ModelControllerClientOperationHandler$ExecuteRequestHandler$1.execute(ModelControllerClientOperationHandler.java:157)
	at org.jboss.as.protocol.mgmt.ManagementRequestContextImpl$1.doExecute(ManagementRequestContextImpl.java:70)
	at org.jboss.as.protocol.mgmt.ManagementRequestContextImpl$AsyncTaskRunner.run(ManagementRequestContextImpl.java:160)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
	at org.jboss.threads.JBossThread.run(JBossThread.java:320)

[standalone@localhost:9990 /] /subsystem=elytron/kerberos-security-factory=a:add(principal=HTTP/localhost@JBOSS.ORG, path=/somewhere, mechanism-oids=["1.2.840.113554.1.2.2","1.3.6.1.5.5.2"],options={a=b})
{"outcome" => "success"}

18:30:37,430 ERROR [org.jboss.as.controller] (Controller Boot Thread) 

OPVDX001: Validation error in standalone.xml -----------------------------------
|
|  365:     </kerberos-security-factory>
|  366: </credential-security-factories>
|  367: <mappers>
|       ^^^^ 'mappers' isn't an allowed element here
|            
|            Elements allowed here are: 
|              audit-logging                  policy                         
|              authentication-client          providers                      
|              credential-security-factories  sasl                           
|              credential-stores              security-domains               
|              dir-contexts                   security-properties            
|              http                           security-realms                
|              mappers                        tls                            
|
|  368:     <constant-permission-mapper name="default-permission-mapper">
|  369:         <permission class-name="org.wildfly.security.auth.permission.LoginPermission"/>
|  370:         <permission class-name="org.wildfly.extension.batch.jberet.deployment.BatchPermission" module="org.wildfly.extension.batch.jberet" target-name="*"/>
|
| 'mappers' is allowed in elements: 
| - server > profile > {urn:wildfly:elytron:1.0}subsystem
| "
|
| The primary underlying error message was:
| > ParseError at [row,col]:[367,13]
| > Message: WFLYCTL0198: Unexpected element
| >   '{urn:wildfly:elytron:1.0}mappers' encountered
|
|-------------------------------------------------------------------------------

18:30:37,430 ERROR [org.jboss.as.server] (Controller Boot Thread) WFLYSRV0055: Caught exception during boot: org.jboss.as.controller.persistence.ConfigurationPersistenceException: WFLYCTL0085: Failed to parse configuration
	at org.jboss.as.controller.persistence.XmlConfigurationPersister.load(XmlConfigurationPersister.java:143)
	at org.jboss.as.server.ServerService.boot(ServerService.java:376)
	at org.jboss.as.controller.AbstractControllerService$1.run(AbstractControllerService.java:337)
	at java.lang.Thread.run(Thread.java:745)

18:30:37,432 FATAL [org.jboss.as.server] (Controller Boot Thread) WFLYSRV0056: Server boot has failed in an unrecoverable manner; exiting. See previous messages for details.

	"options" => {
	    "type" => OBJECT,
	    "description" => "The Krb5LoginModule additional options.",
	    "expressions-allowed" => false,
	    "required" => false,
	    "nillable" => true,
	    "value-type" => STRING,
	    "access-type" => "read-write",
	    "storage" => "configuration",
	    "restart-required" => "no-services"
	},