The requirement is to not include the min and max values in the sum.
This implies that the value has to be 0 when the input has less than
3 elements. No change needed there.
I think this should have been a 7 Kyu, I liked it.

Reopening dinglemouse's issue:

The Java version needs a bit of a cleanup

static class

public static class AgeDiff {
java.lang.RuntimeException: /AgeDiff.java:1: error: modifier static not allowed here
public static class AgeDiff {

string --> String

public static string CalculateAge(int birth, int yearTo) {
^
symbol: class string

Also the method CalculateAge should be renamed to calculateAge

Would be nice if someone could finally fix this issue.
Nice kata otherwise.

Shouldn't '[]' be removed in optimization?

Instructions are clear and I like Katas that are somehow 'related to the real world'.
Will this ever leave beta? Looking at the responses here it looks like the makers
abandoned ship. :D