i been playing minecraft premium alot but i havnt been playing minecraft classic for a long time. so, i downloaded wom before then put it in a folder. then when i run wom.exe it says download minecraft.jar i did yes or wateva it says and then it asked what type of 3D thing so i chosen hardware then i was searching a server then it it had an error saying....*Minecraft failed to start Java.lang.IllegalAgrumentexeption:input==null!*

Somebody please tell how to fix this...by the way i have an hp computer 

Please help and reply thanks :( :(