The Dropbox desktop application has a helper process called DropboxUpdate.exe, which periodically checks for version updates. DropboxUpdate.exe is a process that must exist on any computer on which Dropbox has been installed. It runs during installation of the Dropbox app, and periodically afterwards to check for and, if needed, update the Dropbox app to the latest available version.
Like Dropbox, DropboxUpdate.exe requires access to the internet. The Dropbox app will notify you if the helper process is unable to contact our servers to check for updates. If you made adjustments to your firewall or antivirus software in order for Dropbox to run, it's likely you'll need to make the same adjustments for DropboxUpdate.exe. If the helper process is unable to update properly for an extended period of time, Dropbox will stop syncing and present you with the following warning message: