A few months ago, a developer on my team had a brain fart and called a key in our storage.yml by a wrong but plausible-sounding name.
The error we saw varied. If it was right after a restart, we saw one error; on the next request after and all subsequent requests, we saw another. I do not remember much if anything about one of these errors – maybe it was in the aws-s3 gem? Maybe in ActiveStorage itself? The other was in seahorse, which is an aws-s3 dependency. I do not remember which error was the “after restart” error and which error was the “all subsequent requests” error.
However, I do remember that neither of them was the kind of error that would lead a reasonable person to diagnose “storage.yml typo” as the cause.