When one door shuts another opens.

The loss of one opportunity does not necessarily end a person's prospects; another possibility may still arise.

The proverb encourages someone facing disappointment to stay open to alternatives instead of treating one ending as the end of every path forward.

Use it to encourage someone after a plan fails or an opportunity ends, particularly when they are ready to consider what to do next. It expresses hope, not a promise that a better outcome will follow.