As straightforward as downloading this mod sounded,i've run into a rough patch. I have very minimal experience in downloading patches and mods, in fact the only experience i would have in it is adding addons to World of Warcraft. I'm receiving a message identifying this download as an "RAR" file, and that i either need to find a source online to unlock it, or something installed on my computer. The big thing i'm worried about is safety, and i just want to download this so i can get on to conquering more civs. I DO NOT have the "Entrenchement" micro-expansion if this has any relevance to the situation. Any and all help would be appreciated, i just want to keep enjoying my investment.