mrchimp/core — comment on commit d82de2c8fe83869d8f1e690c41b5a48adf12c837
File:  line 0
By danimalweb:

Good point. Maybe something like: Config file for HOST not found. Without folder and .php.
This way the user knows what server they are on too, so it could be a simple case that they are trying to use the wrong file.