You need to upgrade your local postgres to get the last security patch from the 2018-03-01, like Heroku did the 1st march. You need one of the last releases 10.3, 9.6.8, 9.5.12, 9.4.17, and 9.3.22.
The security patch can be found here https://www.postgresql.org/about/news/1834/.
It seems the patch modified pg_dump, that’s probably why we can’t use pg_restore anymore without that patch for the dump of Heroku (with the patch applied).