Log in to dropbox.com and click Shared in the left sidebar. Then, navigate to Folders, Files, or Links to see what’s been created or shared with you. If you don't see the link in your list (under Links), you may have removed it at some point. You can always create a new link by going back to the original file of folder and re-sharing it.
Dropbox team users can set passwords and expiration dates for shared links. See if you’ve shared the password with the user or if the expiration date for your shared link has expired. In that case, you need to share the password or create a new link to the file or folder.
You may also have restricted settings on the folder the file is stored in. Make sure the folder settings allow for links to be shared with people outside of this folder.
If you clicked a shared link and were sent directly to your Dropbox account, you already had access to this file—the link has taken you directly to the file's location. This works for folders too. If you already have a folder in your account, its link will take you to the location of that folder and you can get back to work!
This feature gives you easier access to the files and folders you already have in your Dropbox account. It also helps avoid creating multiple copies of the same file.