New Update Broke Site

I get a fatal error on this site with the latest version of WP Fastest Cache. I have deleted both this and the server cache and still, the site has a fatal error and will not load unless I deactivate it. However, the backend works fine.

I tried rolling back to several previous versions, still get a fatal error. I have not uploaded any new plugins. Has all been working great for years.

I deleted it and tried a fresh install of this plugin – still get a fatal error.

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