Have this in logs

1) WARNING: Unable to resolve resource:Microsoft.ResourceManagement.Workflow.Activities.ApprovalActivity.rules.

2) WARNING: Unable to resolve resource:Microsoft.ResourceManagement.Workflow.Activities.ReceiveCreateResourceActivity.rules.

3) ERROR: Microsoft.IdentityManagement.CredentialManagement.Portal: System.Web.HttpUnhandledException: ScriptManager_AsyncPostBackError ---> Microsoft.ResourceManagement.WebServices.Client.AuthorizationRequiredException: Permission is required
   at Microsoft.ResourceManagement.WebServices.Client.Resource.Update(ClientOptionsHelper clientOptionsHelper)
   at Microsoft.ResourceManagement.WebServices.ResourceManager.ResumableUpdate()
   at Microsoft.ResourceManagement.WebServices.ResourceManager.Resume(ContextualSecurityToken securityToken)
   at Microsoft.IdentityManagement.CredentialManagement.Portal.Components.RegistrationDriver.FinalizeRegistration()
   at Microsoft.IdentityManagement.CredentialManagement.Portal.Registration.Next()
   at System.Web.UI.WebControls.Button.OnClick(EventArgs e)
   at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)
   at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   --- End of inner exception stack trace ---
   at Microsoft.IdentityManagement.CredentialManagement.Portal.Site.ScriptManager_AsyncPostBackError(Object sender, AsyncPostBackErrorEventArgs eventArgs)
   at System.Web.UI.ScriptManager.OnAsyncPostBackError(AsyncPostBackErrorEventArgs e)
   at System.Web.UI.PageRequestManager.OnPageError(Object sender, EventArgs e)
   at System.Web.UI.TemplateControl.OnError(EventArgs e)
   at System.Web.UI.Page.HandleError(Exception e)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest()
   at System.Web.UI.Page.ProcessRequest(HttpContext context)
   at ASP.default_aspx.ProcessRequest(HttpContext context)
   at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

4) WARNING: Invalid or NULL email address

5) ERROR: Microsoft.ResourceManagement.Service: System.ArgumentException: Invalid or NULL email address
   at Microsoft.ResourceManagement.Mail.Utilities.ValidateMailMessage(GenericMessage message, IMailServer mailServer)
   at Microsoft.ResourceManagement.Mail.ApprovalMessage.Send(Int32 timeoutInMilliseconds)
   at Microsoft.ResourceManagement.Workflow.Hosting.SendMailWorkItemProcessor.SendMailMessage(MessageContent messageContent, Int32 timeoutInMilliseconds)
   at Microsoft.ResourceManagement.Workflow.Hosting.SendMailWorkItemProcessor.ProcessWorkItem(WorkItem workItem)

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What is already done:

1) Double checked all setup process with permissions, wmi, dcom, etc.

2) double checked that Fim service account is mail enabled end can successfully reach EWS web page without any issues.

3) All users have e-mail fields filled

4) Totally confused. Don't know where to dig.

Good job summarizing your already taken troubleshooting steps. Is this what happens during registration or reset?

If reset, did the user register? Did you change the workflow after the user did register?