Download fails at x%
You have a proxy that is detecting Metasploit as malware and interrupting the download.
Metasploit is a software that tests whether a system is vulnerable to certain security issues. To do this, Metasploit exploits the same vulnerabilities as common malware and hacking software. This is what your anti-virus program detects and warns you about.
Download Metasploit from outside your network or download without using the proxy.