Can you provide more information about the alert?
Where did it appear? Do you have a screenshot? Were any manual changes made to that file?
Those appear to be 2 different versions of Cache Enabler. Did you recently upgrade the plugin or reinstall it?
I updated to the 1.2.2 version a few days ago (the version was released 6 days ago)
Generally I don’t receive this kind of alert when there’s a plugin update, but it already happened a few times.
I just wanted to know if it’s something to worry about.
This is nothing to worry about as there have simply been a few updates made to the main PHP file in order to improve the plugin. Here is the changelog if you’re interested in what changes were made: https://wordpress.org/plugins/cache-enabler/#developers