i have a link that doesn't work any more because the file was briefly renamed
Moving or renaming a file or folder will render any links to it inactive. You might be able to restore the link if the file is renamed back to the exact name it had previously, but there's no guarantee that will work. If it doesn't work, then you'll need to generate a new link to the file.
[This thread is now closed by moderators due to inactivity. If you're experiencing a similar behavior, feel free to start a new discussion in the Dropbox Community here.]