Social provider not working on azure



The social provider is not working as expected. When I go to admin --> site settings --> social provider and enable and select the groups page and hit save. It does not save the group page settings.

Here is the error is see on eventlog:

Url Rewriting Extension Url Provider Exception:Exception in Url Rewriting Process
Provider Name:DNN Social Url Extension Provider
Provider Version:
Http Status:500 Internal Server Error
Product Version:
Result:Result value null
Exception Type:System.NullReferenceException
Object reference not set to an instance of an object.
Stack Trace:(TRUNCATED TO 500 CHARS): at DotNetNuke.Modules.SocialUrlProvider.UrlController.BuildUrlIndexes(Int32 portalId, SocialUrlProvider provider, FriendlyUrlOptions options, Hashtable& friendlyUrlIndex, Hashtable& queryStringIndex) at DotNetNuke.Modules.SocialUrlProvider.UrlController.GetFriendlyUrlIndex(Int32 portalId, SocialUrlProvider provider, FriendlyUrlOptions options) at DotNetNuke.Modules.SocialUrlProvider.SocialUrlProvider.ChangeFriendlyUrl(TabInfo tab, String friendlyUrlPath, FriendlyUrlOptions options, St
Server Name: RD000D3A1353F7