Error: TypeError: no implicit conversion of nil into string in ‘get mac’

It looks like windows ipconfig has trouble finding a valid MAC address on you computer. Skalp is dependent on ipconfig reporting at least one valid MAC address.
Could you open a windows command line (from the start menu run cmd.exe) and then type:
ipconfig /all

Or, it could be that cmd.exe refuses to run on you system. Then the following should fix the problem:
http://superuser.com/questions/503145/why-ipconfig-does-not-work-on-windows-7
This boils down to adding c:\windows\system32 to your system path so that windows can find cmd.exe again.

Or if you see a MAC address 00:00:00:00:00:E0 then the following should fix the problem:

1. Click Start, type cmd in the “Start Search” box, right click the cmd.exe, and then click Run as Administrator.
2. In the Command Prompt, type: netsh int isa set state disabled, and press Enter.