Error under the footer

Hi, For a few days I have a mistake under the footer on website (benessere-psicofisico.com )
There is a long page with some texts like:
“| 0 | alloptions:options 1008 | cached | internal | 664 | 0 | notoptions:options 1009 | cached | internal | 237618 | 0 | alloptions:options 1010 | cached | internal | 664 | 0 | ”
If I disable w3 total cache the problem disappears.

How do I fix it?
thanks