Parijs on "[Plugin: W3 Total Cache] W3TC won't activate minify"

i am using: wp version 3.9 en w3tc Versie: 0.9.4.

I try to activate minify.

If i go to w3tc > general > check the box and hit save.

When i did that the checkbox goes back unchecked.

Sombody a idea?

https://wordpress.org/plugins/w3-total-cache/