When an artefact is archived it can't be downloaded if its file size is >=2GB.

Steps for upload failure:
1. Setup a project that takes a file paremeter
2. Start a new build, it asks for a file to be uploaded
3. Select a file thats >=2GB
4. The page 404's

Steps for download failure:
1. Setup a project that archives artefacts
2. The actual build that causes this issue generates a huge zip file (about 2.5GB), the zip file is created using 7z NOT by Jenkins download as zip feature.
3. Attempt to download this using the URL at the end of the build, it will 404, yet the download as zip or the "view" link appears to work ok