Evaluation of java snippet failed for row "Row 0": org/dom4j/DocumentException

The problem ist that the dom4j-1.6.1.jar file is missing, please add it to the additional libraries. You find it in the ooxml-lib folder of poi.

I have to hints to debug thes kind of issues. The exception is throw before your script is excuted. When you adjust the log level in your KNIME preferences you will see the exception in the KNIME console window.

Secondly, there is a way to log errors within your Java Snippe script. Yo can use logError("an error or exception") to utilize the KNIME logging system.