HI! I'm doing an exercise on antlr. An it works on different computers, but when i try it on my computer it doesn't. So i don't know what is wrong. I keep getting an error: http://shrani.si/f/2Z/JM/sLDMu6K/error.jpg I tried differend prgrams and they all put out this error. What should i do? Please help. Thanks in advance!