If logback.xml is not available as a file (for example it is in a jar in the lib folder of a webapp) logback logs an error during configuration. The reason is that in ch.qos.logback.core.joran.spi.ConfigurationWatchList.convertToFile(URL) method it tries to convert the url to file and if it fails it marks this as an error. Imho it should simply silently not do anything in this case.