Validation error on optional properties.

If this problem was discovered on a version of Drupal that is not 11.x, add that information in the issue summary and leave the version at 11.x. In Drupal core changes are made on on 11.x (our main development branch) first, and are then back ported as needed according to the Core change policies → . Also mentioned on the version → section of the list of issue fields documentation.

Added the fix for the problem. A test for the case is needed.

Thanks for reporting this issue. While the patch adds null as a valid type for top-level non-required properties, those properties may themselves have child properties that are not yet handled.

Instead of adding null as a type, can we instead skip validation for properties that are both optional and null?

Works fine with Drupal 10