Error 500 with Testimonial Slider

When I access to a page with a Testimonial Slider, the server launched a error 500, I contact with the hosting, and said me which the problem is a programation problem:

End of script output before headers: index.php

I removed the Slider Testimonial and the issue when access to a page disappear.
I must put the Testimonial Slider, I wait for your response.