Null pointer exception when client login theme is not set

We’ve added a custom theme just by copying and renaming the default folder and doing some changes.
In the realm settings we have set our custom theme in all the theme settings (login/account etc).

When logging in via an external provider (google, fb) and keycloak has to show an error we get this exception:

09:44:57,216 WARN  [org.keycloak.services] (default task-1) KC-SERVICES0013: Failed authentication: java.lang.NullPointerException
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.theme.DefaultThemeManager.loadTheme(DefaultThemeManager.java:106)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.theme.DefaultThemeManager.getTheme(DefaultThemeManager.java:73)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.theme.DefaultThemeManager.getTheme(DefaultThemeManager.java:62)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.forms.login.freemarker.FreeMarkerLoginFormsProvider.getTheme(FreeMarkerLoginFormsProvider.java:289)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.forms.login.freemarker.FreeMarkerLoginFormsProvider.createResponse(FreeMarkerLoginFormsProvider.java:177)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.forms.login.freemarker.FreeMarkerLoginFormsProvider.createUpdateProfilePage(FreeMarkerLoginFormsProvider.java:519)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.authentication.authenticators.broker.IdpReviewProfileAuthenticator.authenticateImpl(IdpReviewProfileAuthenticator.java:67)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.authentication.authenticators.broker.AbstractIdpAuthenticator.authenticate(AbstractIdpAuthenticator.java:76)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.authentication.DefaultAuthenticationFlow.processSingleFlowExecutionModel(DefaultAuthenticationFlow.java:438)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.authentication.DefaultAuthenticationFlow.processFlow(DefaultAuthenticationFlow.java:247)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.authentication.AuthenticationProcessor.authenticateOnly(AuthenticationProcessor.java:976)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.services.resources.LoginActionsService$1.authenticateOnly(LoginActionsService.java:792)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.authentication.AuthenticationProcessor.authenticate(AuthenticationProcessor.java:838)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.services.resources.LoginActionsService.processFlow(LoginActionsService.java:313)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.services.resources.LoginActionsService.brokerLoginFlow(LoginActionsService.java:822)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.services.resources.LoginActionsService.firstBrokerLoginGet(LoginActionsService.java:716)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:138)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.ResourceMethodInvoker.internalInvokeOnTarget(ResourceMethodInvoker.java:526)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTargetAfterFilter(ResourceMethodInvoker.java:415)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.ResourceMethodInvoker.lambda$invokeOnTarget$0(ResourceMethodInvoker.java:376)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.interception.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:356)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:378)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:347)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:150)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:104)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:440)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.SynchronousDispatcher.lambda$invoke$4(SynchronousDispatcher.java:229)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.SynchronousDispatcher.lambda$preprocess$0(SynchronousDispatcher.java:135)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.interception.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:356)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.SynchronousDispatcher.preprocess(SynchronousDispatcher.java:138)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:215)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:227)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56)
    at org.jboss.resteasy.resteasy-jaxrs@3.11.0.Final//org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:51)
    at javax.servlet.api@2.0.0.Final//javax.servlet.http.HttpServlet.service(HttpServlet.java:590)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:74)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129)
    at org.keycloak.keycloak-services@10.0.0//org.keycloak.services.filters.KeycloakSessionServletFilter.doFilter(KeycloakSessionServletFilter.java:91)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.ServletChain$1.handleRequest(ServletChain.java:68)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
    at org.wildfly.extension.undertow@19.0.0.Final//org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
    at io.undertow.core@2.0.30.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.RedirectDirHandler.handleRequest(RedirectDirHandler.java:68)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:132)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
    at io.undertow.core@2.0.30.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.core@2.0.30.Final//io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
    at io.undertow.core@2.0.30.Final//io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)
    at io.undertow.core@2.0.30.Final//io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)
    at io.undertow.core@2.0.30.Final//io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
    at io.undertow.core@2.0.30.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at org.wildfly.extension.undertow@19.0.0.Final//org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
    at io.undertow.core@2.0.30.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at org.wildfly.extension.undertow@19.0.0.Final//org.wildfly.extension.undertow.deployment.GlobalRequestControllerHandler.handleRequest(GlobalRequestControllerHandler.java:68)
    at io.undertow.core@2.0.30.Final//io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:269)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:78)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:133)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:130)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43)
    at org.wildfly.extension.undertow@19.0.0.Final//org.wildfly.extension.undertow.security.SecurityContextThreadSetupAction.lambda$create$0(SecurityContextThreadSetupAction.java:105)
    at org.wildfly.extension.undertow@19.0.0.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1541)
    at org.wildfly.extension.undertow@19.0.0.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1541)
    at org.wildfly.extension.undertow@19.0.0.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1541)
    at org.wildfly.extension.undertow@19.0.0.Final//org.wildfly.extension.undertow.deployment.UndertowDeploymentInfoService$UndertowThreadSetupAction.lambda$create$0(UndertowDeploymentInfoService.java:1541)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:249)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:78)
    at io.undertow.servlet@2.0.30.Final//io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:99)
    at io.undertow.core@2.0.30.Final//io.undertow.server.Connectors.executeRootHandler(Connectors.java:376)
    at io.undertow.core@2.0.30.Final//io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:830)
    at org.jboss.threads@2.3.3.Final//org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35)
    at org.jboss.threads@2.3.3.Final//org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:1982)
    at org.jboss.threads@2.3.3.Final//org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1486)
    at org.jboss.threads@2.3.3.Final//org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1377)
    at java.base/java.lang.Thread.run(Thread.java:834)

Full log available here

if we set the login theme in the client app to the same value as the realm login theme it works, any idea why? Any misconfiguration from our side?

Thank you!