Today decided to test Netbeans 6.0.1. I was satisfied with 6.0 but I had a stupid problem with JAX-RPC which prevented to use that feature. Instead of trying to solve that decided to move on to this version. So I downloaded the OS independent zip - this is what I like after all - but when I started... ooops. I got a message that Ruby and Rails version is not correct. So what? Try to upgrade. Same error again. What a shame. Decided to uninstall the Ruby and Rails and restart. Did not help. Deleted ruby files from ~/.netbeans/6.0/modules also did not help. Finally I solved this problem with starting the IDE and updating only IDE Platform first. Since that I could not reproduce the error and I have no time now to play more with this. So if you are having this make a try. But I will try to find out the real reason as soon as I will have some time.