Nmap 5.51: Zenmap: Error Saving Snapshot: Surface.write_to_png takes one argument which must be a filename (str)
I upgraded to Nmap 5.51 early this afternoon because a friend asked me to take a look at creating a topology image of a network scan of around 3,000 hosts. After upgrading I opened his scan in Zenmap and attempted to export the topology of the scan as a PNG but I received an error which I at first assumed was an issue on my computer or an issue with the fact that the export to PNG image was taking place on a 64-bit Windows 7 computer however both of those turned out to be incorrect. Below I describe the error in more detail as well as the current newest Nmap version that will allow PNG export, a workaround for the issue, and notes about the response from the Nmap development team that already pushed a fix to SVN only a couple hours after the issue was reported (+1 Nmap devs!).