Doug, okay. I think that you might have two choices:
1) Ignore it. It is only a warning.
2) Get opcache working on your site. This will remove the warning message, and make your Moodle perform a little better.
Which solution do you prefer?
I do see some others helping too. Maybe you already have this problem resolved.
I actually picked #2 for my small moodle. Yep, a little editing of php.ini necessary, but not too bad.
(I will watch for your posts.)