Issues after subscription criteria

Hi! All,

I am having this weird issue. I have a bunch of urls added via "web application avilability monitoring", put all the urls under a new MP called "MP for URL". Now I want to add a subscription, so created a subscription with criteria"created by specific rules or monitors".

Under "Monitor and rule search" I selected "MP for URL" and hit search. I expected for all the urls to be listed, so I could select the one related to the subscription name. But I get a pop-up message with the following messaeg

The same issue happens when I select "Web Application Availability Monitoring Library"

Here is the below ERROR:

The provided collection was either null or empty.

Parameter name: ids

Date: 9/16/2013 3:58:49 PM
Application: Operations Manager
Application Version: 7.0.9538.1068
Severity: Error
Message: The provided collection was either null or empty.
Parameter name: ids

System.ArgumentOutOfRangeException: The provided collection was either null or empty.
Parameter name: ids
   at Microsoft.EnterpriseManagement.ValidationHelper.ValidationCollection[T](ICollection`1 collection, String paramName)
   at Microsoft.EnterpriseManagement.EntityTypeManagement.GetClasses(ICollection`1 ids)
   at Microsoft.EnterpriseManagement.Mom.Internal.UI.Dialogs.PickerDialogs.MonitorAndRulePickerControl.GetRequiredClasses(IManagementGroupSession groupSession, IList`1 rules, IList`1 monitors)
   at Microsoft.EnterpriseManagement.Mom.Internal.UI.Dialogs.PickerDialogs.MonitorAndRulePickerControl.GetSources(String criteriaString, IManagementGroupSession groupSession)
   at Microsoft.EnterpriseManagement.Mom.Internal.UI.Dialogs.PickerDialogs.MonitorAndRulePickerControl.Search(CancelFlagWrapper cancelFlag)
   at Microsoft.EnterpriseManagement.Mom.Internal.UI.AsyncChooserDialogItemProvider.SearchAsyncBegin(Object sender, DoWorkEventArgs e)
   at System.ComponentModel.BackgroundWorker.WorkerThreadStart(Object argument)

Pl appreciate some quick help.

Many thanks

Ven