LinkageError: loader constraint violation: when resolving field "NODE" the class loader (instance of org/codehaus/groovy/tools/RootLoader) of the referring class, javax/xml/xpath/XPathConstants,

See

This reported that the “stax-api-1.0.1.jar” bundled in the v7.9.1 caused the problem LinkageError: loader constraint violation: when resolving field “NODE”

In the .classpath of @youssef.machkira I found a line:

	<classpathentry kind="lib" path="D:/Katalon_Studio_Windows_64-8.1.0/configuration/resources/lib/stax-api-1.0.1.jar"/>

So the error occured again due to the same reason as I reported previously.

@youssef.machkira

Please try removing the stax-api-1.0.1.jar from your Katalon Studio v8.1.0.