As the title says, the file cannot be downloaded. I tried to download it manually, but the the download link appears to be broken. What can i do now?
Sorry for the trouble, didn’t know MS was actually removing DL links of RC.
We will release a new version of Paradox today that will fix this (amongst many other things).
In the meantime, just install http://www.microsoft.com/en-us/download/details.aspx?id=48159 before installing Paradox and you should be fine (try to uninstall/reinstall 1.2.1 after you are done if you want to make sure other prerequisites are properly checked).
Paradox 1.2.2 should now properly install Build Tools 2015 RTM.