Cancelling the other downloads helped. I noticed the downloads are throttled, so maybe I was penalized from xenforos server for having multiple downloads at the same time. Anyway, it works now. Thanks for your help.
It's odd that it is happening in multiple browsers.
Can you try it on a different device? And a different internet connection? For the latter I would often connect to my mobile phone personal hot spot as that would bypass my normal router and internet connection and therefore confirm or deny that is the issue.