Heroes 5.5 WarGame Edition - Tactical Edition.

I don't have only this mod installed

Added 2 minutes ago
I have all mods removed. Could it be because I have version 3.0 of Heroes?

This mod is for version 3.1.

In 3.0, at least the main settings file is different, so it doesn't recognize some of the WGE settings. Update to 3.1.