Yes, I can edit the files and already know how to do that after several years of working with WordPress. I can even edit them offline and upload new copies if needed. That is not the problem. The problem is an incorrect check for permissions as far as I can see. I would like to have that fixed so that I can recommend this plugin to clients.
I install and configure CMS sites for clients, but I am not a PHP guru by any means. So, this error stops me from being able to use IceCaptcha for my clients who are most definitely not comfortable with editing the source files. If I knew where and what to edit to change the permission checks and stop this error message, I would do that and use a modified IceCaptcha for clients.