MB4 253b: Gentile Absentee Ownership and Eruvei Chatzeros (383:1); Gentile Guests and Eruv Chatzeros (384:1)

If a gentile owns a house in a courtyard with 2 or more Jews and is away for Shabbos: if they didn't acquire rights from him and he returns on Shabbos, his presence ruins the eruv chatzerot. They can still do a bitul reshut.

If he is more than a day's journey away the Jews don't need to acquire rights from him.

What if the gentile owner passes away over Shabbos?

If a gentile enters a Jew's house as a guest on Shabbos does he invalidate the eruv chatzerot?