Get errors in RE2

[zackymony]

when opening the editor in game,the nodes disappear and got this error

and the node:get_full_name() seems to have some trouble too.I change them all into "unknown" to temporarily fix it.

`
for i=0, tree:get_node_count()-1 do
local node = tree:get_node(i)

        if node then
            local insertion = {
                name = "unknown",
                children = {}
            }
            **for j=0, #node:get_data():get_children()-1 do
                local child_index = node:get_data():get_children()[j]
                table.insert(insertion.children, child_index)
            end**

            table.sort(insertion.children)

            custom_tree[i] = insertion
        end
    end`