I haven't completely investigated this, but Nmap 7.80 on Windows 10 is crashing with a segfault when I scan my HP OfficeJet Pro 8720 against port 80 using the http-robots.txt script. I have tried using a Windows 10 VM and also Windows 10 on a Dell XPS 12 laptop. The bug might be in the HTTP library rather than the script. I do not get the crash when I scan using the same command with latest SVN build (9/3/19) from Linux. This seems to be a regression with Nmap 7.80 as it does not happen if I downgrade the Windows VM to Nmap version 7.70. I have attached a screenshot of the crash.