This is last version of Hegemonia City States. Launch the installer and install it into "Rome - Total War/BI". The shorcut that the installer has created automatically in your desktop doesn't work. You will have to create a new shorcut of RTW-BI.exe. Then, right-click on it and click on "Properties". Add " -mod:bi/hcs -show_err -nm" in the target line, then click "Ok". Use this new shortcut to launch the mod.