In my Keycloak setup, StackOverflow is configured as one of the login providers. Recently, I noticed that new users are unable to register on my site via StackOverflow because the returned email is null. What could be the reason for this?
keycloack.version 18.0.2
2024-09-02 10:39:51,276 WARN [org.keycloak.services] (executor-thread-11964) KC-SERVICES0020: Email is null. Reset flow and enforce showing reviewProfile page
2024-09-02 10:39:51,276 WARN [org.keycloak.services] (executor-thread-11964) KC-SERVICES0013: Failed authentication: org.keycloak.authentication.AuthenticationFlowException
at org.keycloak.authentication.AuthenticationProcessor.authenticateOnly(AuthenticationProcessor.java:1038)
at org.keycloak.services.resources.LoginActionsService$1.authenticateOnly(LoginActionsService.java:808)
at org.keycloak.authentication.AuthenticationProcessor.authenticate(AuthenticationProcessor.java:892)
at org.keycloak.services.resources.LoginActionsService.processFlow(LoginActionsService.java:323)
at org.keycloak.services.resources.LoginActionsService.brokerLoginFlow(LoginActionsService.java:838)
at org.keycloak.services.resources.LoginActionsService.firstBrokerLoginGet(LoginActionsService.java:732)
at jdk.internal.reflect.GeneratedMethodAccessor343.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:170)
at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:130)
at org.jboss.resteasy.core.ResourceMethodInvoker.internalInvokeOnTarget(ResourceMethodInvoker.java:660)
at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTargetAfterFilter(ResourceMethodInvoker.java:524)
at org.jboss.resteasy.core.ResourceMethodInvoker.lambda$invokeOnTarget$2(ResourceMethodInvoker.java:474)
at org.jboss.resteasy.core.interception.jaxrs.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:364)
at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:476)
at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:434)
at org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:192)
at org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:141)
at org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:32)
at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:492)
at org.jboss.resteasy.core.SynchronousDispatcher.lambda$invoke$4(SynchronousDispatcher.java:261)
at org.jboss.resteasy.core.SynchronousDispatcher.lambda$preprocess$0(SynchronousDispatcher.java:161)
at org.jboss.resteasy.core.interception.jaxrs.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:364)
at org.jboss.resteasy.core.SynchronousDispatcher.preprocess(SynchronousDispatcher.java:164)
at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:247)
at io.quarkus.resteasy.runtime.standalone.RequestDispatcher.service(RequestDispatcher.java:73)
at io.quarkus.resteasy.runtime.standalone.VertxRequestHandler.dispatch(VertxRequestHandler.java:151)
at io.quarkus.resteasy.runtime.standalone.VertxRequestHandler.handle(VertxRequestHandler.java:82)
at io.quarkus.resteasy.runtime.standalone.VertxRequestHandler.handle(VertxRequestHandler.java:42)
at io.vertx.ext.web.impl.RouteState.handleContext(RouteState.java:1212)
at io.vertx.ext.web.impl.RoutingContextImplBase.iterateNext(RoutingContextImplBase.java:163)
at io.vertx.ext.web.impl.RoutingContextImpl.next(RoutingContextImpl.java:141)
at io.quarkus.vertx.http.runtime.StaticResourcesRecorder$2.handle(StaticResourcesRecorder.java:67)
at io.quarkus.vertx.http.runtime.StaticResourcesRecorder$2.handle(StaticResourcesRecorder.java:55)
at io.vertx.ext.web.impl.RouteState.handleContext(RouteState.java:1212)
at io.vertx.ext.web.impl.RoutingContextImplBase.iterateNext(RoutingContextImplBase.java:163)
at io.vertx.ext.web.impl.RoutingContextImpl.next(RoutingContextImpl.java:141)
at io.quarkus.vertx.http.runtime.VertxHttpRecorder$5.handle(VertxHttpRecorder.java:380)
at io.quarkus.vertx.http.runtime.VertxHttpRecorder$5.handle(VertxHttpRecorder.java:358)
at io.vertx.ext.web.impl.RouteState.handleContext(RouteState.java:1212)
at io.vertx.ext.web.impl.RoutingContextImplBase.iterateNext(RoutingContextImplBase.java:163)
at io.vertx.ext.web.impl.RoutingContextImpl.next(RoutingContextImpl.java:141)
at org.keycloak.quarkus.runtime.integration.web.QuarkusRequestFilter.lambda$createBlockingHandler$1(QuarkusRequestFilter.java:71)
at io.vertx.core.impl.ContextImpl.lambda$null$0(ContextImpl.java:159)
at io.vertx.core.impl.AbstractContext.dispatch(AbstractContext.java:100)
at io.vertx.core.impl.ContextImpl.lambda$executeBlocking$1(ContextImpl.java:157)
at io.quarkus.vertx.core.runtime.VertxCoreRecorder$13.runWith(VertxCoreRecorder.java:543)
at org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2449)
at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1478)
at org.jboss.threads.DelegatingRunnable.run(DelegatingRunnable.java:29)
at org.jboss.threads.ThreadLocalResettingRunnable.run(ThreadLocalResettingRunnable.java:29)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Thread.java:833)
2024-09-02 10:39:51,277 WARN [org.keycloak.events] (executor-thread-11964) type=IDENTITY_PROVIDER_FIRST_LOGIN_ERROR
N.B: My answer is based on latest Keycloak version 25.0.4. It may or may not be applicable to your old version 18.0.2
Did you modify the authentication flow for login using identity provider? The "Review Profile" step needs to be "Required" to allow users to add the missing email address.