Você estava certo, aqui está o erro anterior:
ERROR: could not create unique index "index_tags_on_lower_name"
DETAIL: Key (lower(name::text))=(زبا�) is duplicated.
EXCEPTION: psql failed: DETAIL: Key (lower(name::text))=(زبا�) is duplicated.
Acho que isso já foi relatado aqui: Can't restore due to corrupt indexes (with some clues on how to deal with corrupt indexes) e aqui There are some duplicated tags due to database corruption and I can't merge .