Event Handler Won't Work

Dear all,

Previously I've posted about precedence error that didn't work and now it works, thanks to John Welch for his support. But when I tried to use event handler, it won't work. When error occured it didn't redirect to the OnError event handler. And then I built another package but with Data Flow task only, put a simple Script task inside OnError event handler and strange..it worked fine. There is no differences between my first Data Flow task and the last Data Flow task, totally the same process. I've captured both execution result. This is the first failure Data Flow task and the last success Data Flow Task (failure and success herein means that OnError work or not)

And then I did some testing in my last package contains a success Data Flow task. I put a new Data Flow task by copy from the previous one, execute it and OnError won't work again. Then I delete it, execute the previous one and OnError worked fine. I really don't understand why by adding a new Data Flow Task then OnError event handler won't work ?

Any help would be appreciate. Thanks in advance.

Best regards,

Hery