Sure.
You said “abnormal situation”. So in the case outbox (or lack of outbox) failed, what follows.
How do you hint to the user what is the next step in this sherlock holmes work to find a note. Where do they look, where the app hasnt looked.
Discussion
You don't, because if you knew you would do it yourself.
Unless you're lazy. In that case instead of writing code to do it you write English and tell the user to do it.
Designers how might we help guide users whose nostr app just failed to find a note?
https://github.com/nostrability/nostrability/issues/42
nostr:npub1uapy44zhu5f0markfftt7m2z3gr2zwssq6h3lw8qlce0d5pjvhrs3q9pmv nostr:npub1a7n2h5y3gt90y00mwrknhx74fyzzjqw25ehkscje58x9tfyhqd5snyvfnu nostr:npub1kuc70777tsvj67fl75s2dmy376t97hv05xmyuyshzzy6vhj5q5jstv0eyw nostr:npub1r0rs5q2gk0e3dk3nlc7gnu378ec6cnlenqp8a3cjhyzu6f8k5sgs4sq9ac nostr:npub149p5act9a5qm9p47elp8w8h3wpwn2d7s2xecw2ygnrxqp4wgsklq9g722q
“It appears this note had other plans and showing up wasn’t one of them”
Yes, and besides the nostr:npub180cvv07tjdrrgpa0j7j7tmnyl2yr6yr7l8j4s3evf6u64th6gkwsyjh6w6 type message, whats the next step?
>button< shut it all down, go bloom outside
Error messages for non-compatible features would be nice too.
This note includes a feed, it opens empty on Damus, has just the nostr:addr… on Primal.
nostr:note1n9z7fltdg5u638rfa5gc8k4p5yln4pndvs7wq20esenw3su8lyhq2h0rwc
Nostur has a nice link back to Coracle. Great job nostr:npub1n0sturny6w9zn2wwexju3m6asu7zh7jnv2jt2kx6tlmfhs7thq0qnflahe
#networkeffects 
Thanks nostr:npub1a7n2h5y3gt90y00mwrknhx74fyzzjqw25ehkscje58x9tfyhqd5snyvfnu
I think this points to handling unknown event kinds, and recommended app handler NIPs, which damus has yet to implement.
Nice work nostr:npub1n0sturny6w9zn2wwexju3m6asu7zh7jnv2jt2kx6tlmfhs7thq0qnflahe !
Thanks nostr:npub1a7n2h5y3gt90y00mwrknhx74fyzzjqw25ehkscje58x9tfyhqd5snyvfnu and nostr:npub1zafcms4xya5ap9zr7xxr0jlrtrattwlesytn2s42030lzu0dwlzqpd26k5, this is indeed handling of unknown event kinds, I added this after nostr:npub1l2vyh47mk2p0qlsku7hg0vn29faehy9hy34ygaclpn66ukqp3afqutajft suggested it in nostr:note16pgkeuxvkl3y8c7zgn9zvnn8w4xwqals9henwag5edez3gx8e9wqm33qep
More clients should implement this, its one of the few ways we leverage the current kind-1 network effect to grow the Other Stuff
I just realized that Nostrudel has this thing already and it's pretty cool. I wonder what you think about Nostrudel since it surely looks like a big developer toolbox with a million options, but I like it.
it's for sure the most advanced client
I havent used nostrudel enough to reach this unhappy path of not finding a note.
Can you share a screenshot of what happens on nostrudel in this case?
Personally I nerd out on all the things on nostrudel. Probably its great for many nostr folks today who appreciate all the experimentation.