Error 500 when i send form

[Yakacommuniquer]

Hi, (sorry for my english)

When i send a form, i have a error 500. he go to:
index.php?option=com_ckforms&view=ckforms&task=send&id=1

But i recieved good the form on my mail.

I've actived url rewritting (3 options on) but when desactivated,it doesn't work too.

Thanks for you reponse.