Exclude Widget From Loading On Certain Posts But Load On All Others

This solution enables you to add your after post widget to most single posts and exclude from some.

Based on this question from a member:

How do I stop the after post widget appearing on certain posts? In terms of posts I don’t want the widget to appear on, I haven’t created the posts as yet, so if you can tell me how to do it (such as adding their ID to your code), that would be great.