Weird line of code (dividing by zero)

This may be a plugin or theme conflict. Please attempt to disable all plugins, and switch to the default Twenty Twenty theme. If the problem goes away, enable them one by one to identify the source of the problem.

If you can install plugins, install Health Check. On the troubleshooting tab, you can click the button to disable all plugins and change the theme for you, while you’re still logged in, without affecting normal visitors to your site.

It looks like caching is blocking the actual error or throwing the error. If you configured it, try to check your configuration or temporarily turn it off to see the error. If not try clearing the cache or disabling it in the plugin which is generating the cache.