title: Keycloak: "Account Already Exists" dialog displayed intermittently when I attempt to log in for the first time
body: <p>I'm seeing a strange scenario in Keycloak:</p>
  
  <ul>
  <li>Configure Keycloak as an Identity Broker.  It talks to one Identity Provider</li>
  <li>Log in as a user from the Identity Provider</li>
  <li>Occasionally (maybe 1 in every 20 tries), a "Account Already Exists" dialog is displayed.  I have never logged in as this user before.</li>
  </ul>
  
  <p>Any ideas as to why this is happening?  Keycloak version 5.0.0.</p>
  
  <p>Stack trace that is reported when this happens is:</p>
  
  <pre><code>keycloak_1       | 2019-05-07 20:57:06,598 ERROR [org.keycloak.broker.oidc.AbstractOAuth2IdentityProvider] [cid: 9d4851670ce44e17a39a8910c2a3f24d] (default task-13) Failed to make identity provider oauth callback: java.lang.IllegalStateException: Not found in database
  keycloak_1       |  at org.keycloak.models.cache.infinispan.UserAdapter.getDelegateForUpdate(UserAdapter.java:67)
  keycloak_1       |  at org.keycloak.models.cache.infinispan.UserAdapter.setSingleAttribute(UserAdapter.java:136)
  keycloak_1       |  at org.keycloak.broker.provider.HardcodedAttributeMapper.updateBrokeredUser(HardcodedAttributeMapper.java:97)
  keycloak_1       |  at org.keycloak.services.resources.IdentityBrokerService.updateFederatedIdentity(IdentityBrokerService.java:968)
  keycloak_1       |  at org.keycloak.services.resources.IdentityBrokerService.authenticated(IdentityBrokerService.java:578)
  keycloak_1       |  at org.keycloak.broker.oidc.AbstractOAuth2IdentityProvider$Endpoint.authResponse(AbstractOAuth2IdentityProvider.java:432)
  </code></pre>