One of my files failed, and it was really big. What can I do?
If you have a very large file (bigger than 4 GiB) which refuses to download correctly, it may be possible that your local filesystem doesn't support files that big. This can happen on old versions of Windows, or if you are downloading to a USB stick formatted with an old filesystem. In this case, we recommend switching to a different computer or a different disk. It may also help to download the file individually through the U1 web interface, so that you won't have to re-download all your other files: https://one.ubuntu.com/files/
The "FAT32" file system used by Windows, which is also the default filesystem on most USB sticks, does not allow files bigger than 4 GiB. However, Windows also supports NTFS and exFAT, which both handle large files better.
On other platforms (Linux and MacOS), large files should not be a problem unless you attempt to save them to a USB stick or other FAT32-formatted disk.