I managed to download it fine. However the progress bar on my browser was moving fast and repeatedly from left to right instead of growing steadily and slowly during the download, which usually means the browser doesn't know the size of the file being downloaded. It does the same when downloading from APM. The archive has decompressed fine. Perhaps some people have had internet connection issues, or maybe Swisstransfer has had a few issues themselves. The actual archive is fine.
Exactly. If I may add, that also happens every time when you're downloading an archive of selected files (by your choice) from Google Drive.
Swisstransfer does this trick as well, they register a one-time link address for the file you want to download, and it is valid until the file has completed downloading. But it is only clickable once, otherwise you'll have to perhaps refresh the page, perhaps.
So in general, the browser (or rather a 3rd party web downloader i.e IDM) doesn't know the size of that file until it has completed downloading all of the bytes that were provided in that link address. In some cases, even resuming that same file is not possible unless you're using a new link for a new download session of that same file.
