Hello, I use : j2sdk 1.4.2_08 ant 1.6.2-2 libant1.5-java 1.5.4-4 libant1.6-java 1.6.5-1 When I start ant. I recev mesage: Invalid implementation version between Ant core and Ant optional tasks. core : 1.6.5 optional: 1.6.2 Help me for resolv this bug.