Macros are a way to add additional functionality and tools to an existing program, using Visual Basic for Applications, a computer coding language. Like any piece of software, they are usually used for good purposes, but could be used to create a virus. Because of this, Microsoft limits the use of macros unless users specifically enable them.
In the SEAD Street Lighting Tool, macros are used to calculate the results for multiple fixtures, and to perform some other basic tasks of the tool like saving and deleting scenarios. They are also used to access other files on your computer when you add photometric data from an IES file – this is the only time macros are used to do anything outside of the tool file itself.
When opening the file, you may see error messages or warnings that the file may be unsafe or dangerous. This is because of the potential to use macros to create a virus. However, the SEAD tool is safe to use on your computer, and you should enable macros to use the tool. To do so, follow the instructions here, depending on your Excel version: