Could not create SSL/TLS secure channel from dotnet web application

Hi,

In our web application we have social app integration (like facebook, linkedin), when we try to connect facebook or linkedin from our application, its throwing error like and its not connecting to facebook, twitter and linkedin

("System.Net.WebException: The request was aborted: Could not create SSL/TLS secure channel.\\\\\\\\r\\\\\\\\n   at System.Net.HttpWebRequest.GetResponse()\\\\\\\\r\\\\\\\\n   at cotcwebmethods.FbAccesstoken_Register(Nullable`1 ID, String clientID, String AccessToken, String UserID, String UserName, String UserImage, String Email)

but the function works for sometimes when i recycle my application pool from IIS, can you please guide me in this issue.