ES UNA ESTUPIDEZ :3Edit
Macros in Arena.Xlsm are safe and don't do anything to your computer. Arena.Xlsm uses a lot of macros to accomplish gameplay within a spreadsheet. These macros do fun video game stuff rather than boring Autosum stuff!
How do I enable macros?Edit
The method for running macros will vary depending on what version of Microsoft Excel you are using.
Excel 2008: Sorry, this version of excel is not compatible with Arena.Xlsm because it cannot run VBA macros.
Excel 2011: Sorry, this version of excel is not compatible with Arena.Xlsm because it does not support ActiveX controls.
Excel 2013: Microsoft Excel Help Page for Macros