Just wrong. There is the possibility to customize the index number. So, when I save this number in an integer, I expect that my index set is saved to the var.
This worked excellent before the update.
I know that array are indexed from 0 to X. But when 0 to 8 are empty, the index for value of the ninth index would return 0 in this case and this is programmatically completely wrong
I think you misunderstood the way array indexes work. Programmatically you can set any number to an index. Indexes must not be in sequence and they are always retrieved in ascending order. So it's not forbidden to have wholes between index numbers but it can be a bit tricky (even dangerous) in some cases. Having wholes is even not very logical according to arrays.
It's the reason why, if you have keys (indexes) not consecutive, you'd better use dictionary instead. Items will also be retrieved in key ascending order, whenever keys are of string or numeric form.
According to the value of the index returned by Selection Dialog, as I told you previously, it has nothing to deal with the index of an array (if any) but with the rank of the line pressed by the user (1st line=0).
If your array indexes are not consecutive, the index value returned by the Selection Dialog is useless (in this case only)...