Omsi 2 E6x Download New Online

I'll start by confirming whether E6X is an official expansion. A quick search in the Steam store for OMSI 2 doesn't show any official expansions or DLCs with that name. Maybe it's a community-made mod or a third-party mod. Community mods are common in sim games like OMSI, so perhaps there's a popular mod named E6X that users refer to for additional content.