Hey hellroselee,
Checkout this question on the FAQs page I believe it may help or provide some clues about this issue:
-> Browse to: http://lifeinthegrid.com/duplicator-faq
-> Find question: "I got an 500 server error message what should I do?"
If none of those suggestions help, feel free to submit a support ticket and I'll see if there is anything I can find...
Hope that helps!