01課 〜とき 教科書 p.16
When〜
接続：Vて + からでないと／からでなければ + negative/difficult to do
if not… then no…. State a condition that must be completed first for the following action to occur.
注意 / Note：The latter often means impossible, impossible, difficult or inappropriate; Do not use for purely positive results.
比較 / Compare：Other 〜たあとで only says the order; This sample emphasizes prerequisites. Same 課: 〜うちに／〜間／〜間に／〜ところだ(+助詞) — these models are often mistaken for each other, read the 接続 line carefully and then decide.
実物を見てからでないと、買うかどうか決められません。
If I haven't seen the real thing, I can't decide whether to buy it or not.
上司に相談してからでなければ、予定を変更できません。
If you have not discussed it with your superiors, you cannot reschedule.
パスワードを設定してからでないと、このアプリは使えません。
If you have not set a password, you cannot use this application.