SQL Exception

Error Details

File
Error  Index #: 0
Source: .Net SqlClient Data Provider
Class: 20
Number: -1
Procedure:
Message: System.Data.SqlClient.SqlException: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.SqlClient.SqlConnection.Open() at Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteNonQuery(String connectionString, String spName, Object[] parameterValues) at Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteNonQuery(String connectionString, CommandType commandType, String commandText, SqlParameter[] commandParameters) at Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteNonQuery(String connectionString, String spName, Object[] parameterValues) at DotNetNuke.Services.Log.EventLog.DBLoggingProvider.Data.SqlDataProvider.AddLog(String LogGUID, String LogTypeKey, Int32 LogUserID, String LogUserName, Int32 LogPortalID, String LogPortalName, DateTime LogCreateDate, String LogServerName, String LogProperties, Int32 LogConfigID) at DotNetNuke.Services.Log.EventLog.DBLoggingProvider.Data.SqlDataProvider.AddLog(String LogGUID, String LogTypeKey, Int32 LogUserID, String LogUserName, Int32 LogPortalID, String LogPortalName, DateTime LogCreateDate, String LogServerName, String LogProperties, Int32 LogConfigID) at DotNetNuke.Services.Log.EventLog.DBLoggingProvider.DBLoggingProvider.WriteLog(LogQueueItem objLogQueueItem)