C# Mars: Physical connection is not usable

I am creating a web app in which I am using multipleactiveresultSets,

Sometimes I am getting the error like

System.Data.SqlClient.SqlException occurred HResult=0x80131904
Message=Failed to establish a MARS session in preparation to send the request to the server. (provider: SMux Provider, error: 19 - Physical connection is not usable) Source=.Net SqlClient Data Provider
StackTrace:

can anybody help me out here, I don't know why I am getting this error, and the error does not come all the time,