Errors after enabling 'Whole page caching' in cache settings

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Hi, I'm currently finding ways to make my website faster so I tried playing with the cache settings of concrete 5.7, but when I activated 'Whole page caching' (mine's in French so I think it's the equivalent), I started having weird errors.
Then I wanted to undo what I did so I've put it back off and emptied the cache but the problems persist.

Screenshots attached.

Thanks a lot !

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