a connection was successfully established

AttemptOn eLogin(Ser verInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject) +144 arser.Run( RunBehavio r runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +107 arserState Object.Rea dNetworkPa cket() +88 arserState Object.Rea dSni(DbAsy ncResult asyncResult, TdsParserStateObject stateObj) +359 arserState Object.Rea dSniError( TdsParserS tateObject stateObj, UInt32 error) +527 arser.Thro wException AndWarning (TdsParser StateObjec t stateObj) +194 nternalCon nection.On Error(SqlE xception exception, Boolean breakConnection) +4846887 (provider: TCP Provider, error: 0 - The specified network name is no longer available.)] SqlException (0x80131904): A connection was successfully established with the server, but then an error occurred during the login process. I'm including key portions of the Web.Config file and will be happy to post anything else required to help me get this sorted as soon as possible. I don't even know what this is telling me other than it has to do with a connection problem to the SQL server (also hosted by network solutions).

This site worked fine yesterday for most of the day, however when I tried later in the evening, I received the message above followed by about 40 lines of stack information which I'm including below. It is currently hosted at Network Solutions (on a shared server). I am working on a website that I've been tasked with fixing.