Hi Marc, On 2 lipca 2004, 14:20:25, you wrote: MG> I've already have this kind of problems. In my case the cause MG> was that different class loaders have loaded the MG> TestStepSequence and my custom class. Check the class loader MG> used in your ant script (loaderRef attributes). adding loaderRef to taskdef did the job, many thanks Marc! -- ilfrin mailto:ilfrin@poczta.onet.pl