update in a PI (PUT) with redux, error 500 - Internal SERVER ERROR

I'm working in a project in redux, the Api is in laravel 5 and the server php7 and Ubuntu 16.04.

When I create an element (POST) it's Ok. But when I'm update (PUT), it give me an error.

PUT http://ift.tt/2fowTC0 500 (Internal Server Error :3000/e/2:1 Uncaught (in promise) SyntaxError: Unexpected token < in JSON at position 0 What is the problem?

via Chebli Mohamed