The CivicEngage "leaving website" popup has no compliance issues according to WCAG 2.0 A and AA standards.
The fact that we have such a notification is in support of accessibility standards.
There are no error-free sites. It’s a fluid measurement and different scan tools produce different results—there’s a lot that’s open to interpretation. The most important thing you can do is to show an ongoing good-faith effort to keep your content compliant. To learn more about what you can do, please view our tools and resources.