Somebody else has a problem with slight similarity to yours; it might be worth looking at
this thread.
I made a mistake in the code I posted yesterday. Sorry. It says
That should read
Otherwise if there is an exception in the try block, the br will be
null at this point and you will suffer a NullPointerException.
You have a problem with your letters array. You don't actually need it, and you don't need to read into it because you can create a char[] array directly from a String. In fact you did in earlier versions of the code. If you try to read a String <250 characters long into it, you overrun the end of the String and suffer a StringIndexOutOfBoundsException.