Christoph Eckert a écrit : > > java -jar josm.jar > > Exception in thread "main" java.lang.UnsupportedClassVersionError: > org/openstreetmap/josm/gui/MainApplication (Unsupported major.minor > version 49.0) What Java JVM are you using ? On which operating system ? You have to make sure that the SUN 1.5 JVM is used. (java -version)