Why does testing a DB connection cause an IOException in JBoss EAP?

Issue

• When we test a datasource connection through the admin-console or the jmx-console, the following exception is logged to the console:

  13:48:40,936 ERROR [UsersRolesLoginModule] Failed to load users/passwords/role files
  java.io.IOException: No properties file: users.properties or defaults: defaultUsers.properties found
      at org.jboss.security.auth.spi.Util.loadProperties(Util.java:201)
      at org.jboss.security.auth.spi.UsersRolesLoginModule.loadUsers(UsersRolesLoginModule.java:186)
      at org.jboss.security.auth.spi.UsersRolesLoginModule.createUsers(UsersRolesLoginModule.java:200)
      at org.jboss.security.auth.spi.UsersRolesLoginModule.initialize(UsersRolesLoginModule.java:127)
      at sun.reflect.GeneratedMethodAccessor272.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
      at java.lang.reflect.Method.invoke(Method.java:597)
      at javax.security.auth.login.LoginContext.invoke(LoginContext.java:756)
      at javax.security.auth.login.LoginContext.access$000(LoginContext.java:186)
      at javax.security.auth.login.LoginContext$4.run(LoginContext.java:683)
      at java.security.AccessController.doPrivileged(Native Method)
      at javax.security.auth.login.LoginContext.invokePriv(LoginContext.java:680)
      at javax.security.auth.login.LoginContext.login(LoginContext.java:579)
      at org.jboss.security.plugins.auth.JaasSecurityManagerBase.defaultLogin(JaasSecurityManagerBase.java:553)
      at org.jboss.security.plugins.auth.JaasSecurityManagerBase.authenticate(JaasSecurityManagerBase.java:487)
      at org.jboss.security.plugins.auth.JaasSecurityManagerBase.isValid(JaasSecurityManagerBase.java:365)
      at org.jboss.security.plugins.JaasSecurityManager.isValid(JaasSecurityManager.java:160)
      at org.jboss.security.integration.JBossSecuritySubjectFactory.createSubject(JBossSecuritySubjectFactory.java:90)
      at org.jboss.resource.connectionmanager.JBossManagedConnectionPool.testConnection(JBossManagedConnectionPool.java:389)
      ...