TransactionScope Prematurely Completed

Don't forget to supress your select statements from your TransactionScope. In SQL Server 2005 and above, even when you use with(nolock), locks are still created on those tables the select touches. Check this out, it shows you how to setup and use TransactionScope.

using(TransactionScope ts = new TransactionScope {   // db calls here are in the transaction   using(TransactionScope tsSuppressed = new TransactionScope (TransactionScopeOption.Suppress))   {     // all db calls here are now not in the transaction   } } 

I've found that this message can occur when a transaction runs for a longer period than the maxTimeout for System.Transactions. It doesn't matter that TransactionOptions.Timeout is increased, it can't exceed maxTimeout.

The default value of maxTimeout is set to 10 minutes and its value can only be modified in the machine.config

Add the following (in the configuration level) to the machine.config to modify the timeout:

<configuration>    <system.transactions>        <machineSettings maxTimeout="00:30:00" />    </system.transactions></configuration>

The machine.config can be found at: %windir%\Microsoft.NET\Framework\[version]\config\machine.config

You can read more about it in this blog post: http://thecodesaysitall.blogspot.se/2012/04/long-running-systemtransactions.html

I can reproduce the problem. It is a transaction timeout.

using (new TransactionScope(TransactionScopeOption.Required, new TimeSpan(0, 0, 0, 1))){    using (SqlConnection connection = new SqlConnection(connectionString))    {        connection.Open();        using (var sqlCommand = connection.CreateCommand())        {            for (int i = 0; i < 10000; i++)            {                sqlCommand.CommandText = "select * from actor";                using (var sqlDataReader = sqlCommand.ExecuteReader())                {                    while (sqlDataReader.Read())                    {                    }                }            }        }    }}

Throws System.InvalidOperationException with this message:

The transaction associated with the current connection has completed but has not been disposed. The transaction must be disposed before the connection can be used to execute SQL statements.

To solve the problem make your query run faster or increase the timeout.