Can't launch Groovy Console - missing dependency javax/xml/bind/Unmarshaller

Also got the same issue when using java 11.0.2 and groovy 2.5.5 in IntelliJ.

Found this post that helps! https://www.logicbig.com/tutorials/misc/groovy/intellij.html

Basically have to add JAXB dependencies

Also you have to add JAXB dependencies if you are using Groovy 2.5.3 + Java 11 (also check out Java 11 related change). Groovy comes with extra JAXB Jars so we can add them. Open 'Project Structure' dialog, then select 'Dependencies' tab and add the dependencies as shown

Three suggestions are in the release notes for 2.5.1:

http://groovy-lang.org/releasenotes/groovy-2.5.html#Groovy2.5releasenotes-Addendum251

In 2.5.2, probably a week or two away, you won't need to do them - grab the snapshot version from the CI server if you want to try it out now.