Maven repository validation found that org.kie.soup:kie-soup-dataset-elasticsearch pom.xml is invalid according to Maven pom XSD .
The validation error is the following:
When inspecting , it indeed allows the ``combine`` attribute in children of the ``configuration`` element, but not in the ``configuration`` element itself. It is also mentioned in the documentation:
You can control how child POMs inherit configuration from parent POMs by adding combine.children or combine.self attributes to the of the configuration element:
I have tried to move the attribute to relevant children and the resulting pom.xml is valid. For quick validation, this tool  can be used:  shows an example of the violation,  shows a proposed fix.