
Leonardo
I wish the sharing feature of the (free) storage that comes with an ultimate account would be tested more thoroughly because it doesn't seem stable. Often people report not being able to open the link while it hasn't expired, see a black page etc. It's not reliable for business atm
You're right that we've had couple reported issues with sharing feature, since there are different variations that we need to support, external S3, our own storage and then encryption comes in with two different versions V1 and V2.
We don't have automated tests in that area, so when we deploy changes we need manually test different variations... and tricky part is that it could behave differently if you've opened share in a browser that's logged in to some S3Drive account or if it's fresh start.
This creates so many variations to test against that we couldn't capture all the issues from start, but we've been fixing them on the go as they were reported.
If you could provide us couple more details that would help us to build a knowledge where the issue could be, e.g. did you share files or folders or mix, was the root entry a folder, a file or both? Was encryption enabled? Was it V1 or V2? Is it possible that recipient had their own S3Drive account logged in? Did you modify some/all files after they've been shared with others (with V2 encryption keys need to be regenerated/reencrypted/rewrapped, so that creates yet another potential failure point)?
Tl;dr Sorry for these issues. We strive to improve sharing feature as well as improve our testability. Please report a bug with as many details as you can possibly get and even if we can't fix it straight away, it will get added to our list, so we can prioritize our resources. (edited)