Max's post in FSLabs Base Textures Unable to download was marked as the answer
I wouldn't be surprised if your ISP (I can see it but won't reveal it) is blocking our downloads from our origin storage server link. This has happened previously with the same UK-based ISP.
I have replaced the root of these links with our CDN link in the hope that that should solve it for you.
Please attempt to download the files again and also feel free to let me know if there are any other files that have not been switched over to the CDN root link which you're having trouble downloading.