It's three years after these posts started and Upworks still has the same issues. I done multiple projects on Upworks and I haven't been able todownload them without asking the freelancer to email me. Including my current project. I would expect a site such as upworks to get their act toghether. Not impressed.
I'm sorry to learn that this has been a concern for you for sometime now, Nosson.
I checked your account, and I was unable to replicate your issue. I tried downloading files from the Messages page, and the Contract page, and was able to download the files without any errors. On your end, do you have any screen grabs or more information on what happens when you try to download files from your freelancers? I'll be happy to look into it further.
You should be able to click on the the file name to automatically download the file. Please let me know if this isn't the case for you so that I can look into it further.
Once the file you clink on gets opened in the new tab, you can right-click on it and chose the ''save image as'' to download it to your folder.
I hope this helped.