Hello. I have experience the same error.
Steps to re-create.
1. Install wow.js from git to /libraries/wow
2. Install animate.css from git to /libraries/animate.css
3. go to drupal admin site > extend, and installed the following:
- AnimateCSS
- AnimateCSS Block
- AnimateCSS UI
- WOW JS
4. Go to existing block and add animation.
It works when I don't enable wow, but when I enable wow setting, it shows the error "The website encountered an unexpected error. Try again later."
And when I check the reports, it shows "InvalidArgumentException: The configuration property third_party_settings.animatecss_block.wow.enable doesn't exist. in Drupal\Core\Config\Schema\ArrayElement->get() (line 95 of /opt/bitnami/drupal/core/lib/Drupal/Core/Config/Schema/ArrayElement.php)."