Somebody recently told me that there is a minhag one should not visit a cemetery after Chatzos (noon) on Erev Shabbos. Is this a common practice?

Nitei Gavriel (Avelus 2: 82: 11), Gesher Hachaim (32: 5), Kitzur Shulchan Aruch (188: 14), Orchos Rabbenu (p. 304) and others permit to visit a Beis Hachaim on Friday afternoon or Erev Yom Tov. That is the common minhag, although some abstain. Horav Shlomo Miller’s Shlit’a opinion is similar,