Clash with WPML Translation Plugin

Hi,

thanks for your great plugin, it has worked well for me so far. Unfortunately now I have a page translated with WPML and if I go to a translated page I get a 500 error. Once I turn WP Fastest Cache off, the error is gone.

Do you have any idea how to get rid of the error or how to solve this?

Thanks in advance!

The page I need help with: [log in to see the link]