SQL Server transaction isolation level Snapshot cannot be promoted by DTC.

In case you open a transaction scope in .NET code, using isolation level snapshot, then open a connection, leave that connection open, and try to open another connection, you will retrieve an exception saying that a snapshot transaction cannot be promoted.

Well, in this case, you didn’t wanted to promote that transaction. Using the snapshot isolation level, just make sure only one connection is open at a time, and no exception will occur 🙂