Files download improperly if they don't exist any more

[Alzarath]

When attempting to download a file that no longer exists on the Curse website, the tool downloads the error webpage and names it 'download'.

The Twitch/Curse client is somehow able to download these files itself despite this, so there may be hope to fix it here?

Otherwise, it would be great if it could give an error message instead of downloading the web page. Better still, mention the name of the mod that it's failing to download the file of.