When I go under forum - My Settings - > I get following error.  Any suggestions?

Error: User Settings is currently unavailable.
DotNetNuke.Services.Exceptions.ModuleLoadException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.Modules.Forum.UserSettings.SelectMultiTreeItems(DnnTree objTree, Int32 ForumID) at DotNetNuke.Modules.Forum.UserSettings.Page_Load(Object sender, EventArgs e) --- End of inner exception stack trace ---

I tried that earlier but it didn't do it.  The funny thing is that when i log in under an another admin accout, it lets me do that.

What I am trying to do is configure email notification for the forum. So if there any new posts, all users get an email. If I try to do it under host account, I get the error above but I have an another Administrator account, I can do it through that. I am not sure if this is a big issue but I shouldn't have to create additional administrar account. Host account should be able to do it.

Anyways, going back to the email notfication problem. A user gets an automatic email when he is registered to the forum but the posting email notification doesn't work. Any suggestions?

Thanks in advance.