Error message

[Moebiusenterprises]

The error tells you exactly what the problem is. The permissions to access the file are to restrictive. For editing from the Admin the file and directory must be 777 or read, write, execute. You need to change the permissions back to 644.

I'm having a similar issue (but slightly different)
I've used the Define page editor without problems in the past, but now (on plain text) I get the following:

You don't have permission to access /shop/admin/define_pages_editor.php on this server.

That's with a setting of 755. With 777, I get an internal server error
Oddly enough, the same thing has been happening with ezpages, so I'm wondering if a module (or the last update) might be a culprit?

Thanks in advance.