I am getting smush API 500 error

I am getting this error:
Error posting to API: 500 Internal Server Error
Error posting to API: 500 Internal Server Error
Error posting to API: 500 Internal Server Error
Error posting to API: 500 Internal Server Error
I did debuged as far as I could. I created a new local WordPress install with WordPress 3.7 and SmushPro only installed with twenty seventeen theme. Still get the 500 Errors with huge memory limits already set.