I switched my application from using logback.xml to using logback.groovy. I just wanted to try it but off the bat, I much prefer scanning through an easily alphabetized list of loggers in the groovy file to the mess that you get with XML and lots of loggers. However, my hopes for a quick success were dashed when I saw: Groovy classes are not available on the class path. ABORTING INITIALIZION. What must I do to my application classpath to allow logback configuration via groovy? The manual does not seem to have any information on this. Also, I noticed via goggling the issue that JSON causes an issue with groovy. This will also impact me as our application makes use of JSON. Thanks to anyone who can provide this information. Steve Cohen