Problem to execute a Package and Tasks with a certain TransactionOption property.

I have a Package and a DataFlow Task.The Package has TransactionOption=Required.The DataFlow Task has an OLE DB Source and an OLE DB Destination.The DataFlow Task has TransactionOption=Supported.

If I set TransactionOption=NotSupported in the DataFlow Task then the package executes successful. 

What is the problem? 

Thanks in advance.