hello , please i have an issue with IFrame and feedback modules in dnn 8.0.3 doesn't works in french pages im just upgrading from dnn 7.4.1 to 8.0.3 ,and they give me error:

AbsoluteURL:/Default.aspx

DefaultDataProvider:DotNetNuke.Data.SqlDataProvider, DotNetNuke

ExceptionGUID:47bcd1bd-34c2-4837-868b-4779b502eeae

AssemblyVersion:8.0.3

PortalId:0

UserId:2

TabId:93

RawUrl:/Default.aspx?tabid=93

Referrer:http://localhost:8083/Forum/tabid/93/ctl/Login/lan...

UserAgent:Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36

ExceptionHash:VyDa+4jXahfze0fVk1EZfA==

Message:Could not locate the guest user for the board id 1. You might have deleted the guest group or removed the guest user.

StackTrace:

InnerMessage:Could not locate the guest user for the board id 1. You might have deleted the guest group or removed the guest user.

InnerStackTrace:

   à YAF.Core.UserMembershipHelper.<>c__DisplayClass1.<get_guestuserid>b__0()
   à YAF.Core.Services.Cache.HttpRuntimeCache.GetOrSetInternal[T](String key, Func`1 getValue, Action`1 addToCacheFunction)
   à YAF.Core.UserMembershipHelper.get_GuestUserId()
   à YAF.Core.RoleMembershipHelper.UpdateForumUser(MembershipUser user, Int32 pageBoardID, String[] roles)
   à YAF.Core.YafContext.InitUserAndPage()
   à YAF.Core.UserPageBase.get_Page()
   à YAF.Core.UserPageBase.get_PageUserID()
   à YAF.Forum.OnLoad(EventArgs e)
   à System.Web.UI.Control.LoadRecursive()
   à System.Web.UI.Control.LoadRecursive()
   à System.Web.UI.Control.LoadRecursive()
   à System.Web.UI.Control.LoadRecursive()
   à System.Web.UI.Control.LoadRecursive()
   à System.Web.UI.Control.LoadRecursive()
   à System.Web.UI.Control.LoadRecursive()
   à System.Web.UI.Control.LoadRecursive()
   à System.Web.UI.Control.LoadRecursive()
   à System.Web.UI.Control.LoadRecursive()
   à System.Web.UI.Control.LoadRecursive()
   à System.Web.UI.Control.LoadRecursive()
   à System.Web.UI.Control.LoadRecursive() </get_guestuserid>

à System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)