How do I add mod support into Civilization 5 for Mac when I have MainMenu.xml instead of MainMenu.lua?

I'm trying to enable the mod button within the Steam version of Civilization 5 for Mac. When I navigate to:

~/Library/Application Support/Steam/SteamApps/common/sid meier's civilization v/assets/UI/FrontEnd/MainMenu.lua

I do not have MainMenu.lua like this answer suggests I should: instead I have MainMenu.xml which doesnt contain much in the way of text, and doesn't contain the specific line of code.

How can I resolve this?

I had the same issue until after I installed TextWrangler, as the original response suggests. After I installed it and re-opened the G&K file path, there were numerous files I couldn't see before, including MainMenu.xml

Try installing a new text editor? If the files don't appear, you may be able to open it anyway with "Open File by Name..." from within the text editor. Odds are you have the file, you just can't see it; otherwise, it's unlikely your Civ V game would work.

I had this same problem too, with a missing .lua. I kept trying to open it through text wrangler and even text edit but was hitting a wall trying to get into the Civ 5 g&k contents. since im kinda new to macs i got frustrated and merely used the default mac search within "Civilization V: Gods and Kings" for mainmenu. And the .lua popped up even though it was otherwise invisible. Textwrangler auto downloaded some code translation and I was able to open the file and edit the line. Hope this helps.

Lua files use the icon for an executable file, so double check that you aren't just skipping over it since it doesn't use the text file icon. If it's still not there, then try validating the cache, which can be done by right clicking the game in Steam, going to Properties->Local Files->"Verify Integrity of Game Cache." Otherwise, reinstall the game.