The Rebbe and the Eruv in Kfar Chabad
Kfar Chabad has an accepted local eruv. Its existence belongs to the Chabad record and shows that the question is not a slogan against eruvin as such.
An accepted eruv under local Rabbonim
Kfar Chabad has long maintained an eruv accepted by its Rabbonim. Its route rests on the village's own boundaries, streets, population, construction, and communal arrangements.
Residents carry because the local halachic authority accepts responsibility for that system and its continuing supervision.
A valid eruv has a positive place in Chabad
Kfar Chabad demonstrates that Chabad practice is not based on opposition to every eruv. Shulchan Aruch HaRav treats a properly established eruv as a mitzvah and a protection from hotza'ah.
The question is always whether the particular place meets the halachic conditions and has the approval of the Rabbonim responsible for it.
Crown Heights has different facts and a different psak
Crown Heights is a dense Brooklyn neighborhood within New York's continuous street system. Kfar Chabad's walls, roads, population, and local authority do not enclose or decide it.
The Crown Heights Beis Din has ruled directly that the advertised eruv may not be relied upon. The accepted practice of Kfar Chabad gives no permission to carry in Crown Heights.