How do you say in French one door closes another opens?

The most common and idiomatic way to say "one door closes another opens" in French is:

"Une porte se ferme, une autre s'ouvre."

This is a direct translation of the English proverb and captures its meaning perfectly.

Here are some other ways to express the same idea in French:

* "Quand une porte se ferme, une autre s'ouvre." (When a door closes, another opens)

* "Chaque fin est un nouveau début." (Every end is a new beginning)

* "Il y a toujours une lumière au bout du tunnel." (There is always a light at the end of the tunnel)

The best option for you will depend on the specific context and your desired level of formality.