I would like to point you to this thread on pgsql-bugs:
http://www.postgresql.org/message-id/666abab3fe03561c77dbfc661b023985@neslonek.homeunix.org
It seems that, when using a SQL_ASCII encoded database as the initial
connection DB for pgadmin3 and then using the "properties" windows to
set the comment on an UTF-8 encoded database, pgadmin will actually
write the comment in SQL_ASCII encoding on to the UTF-8 database. When
using special characters like the german umlauts (äöü) this causes
pg_restore -C to throw errors because of invalid encoding and it leads
to pg_upgrade to fail completely.
I have tested this with pgadmin3 1.20.0 on Windows 8.1 with Postgres
9.4.5 both on Solaris 11 and Debian Jessie. But we have been bitten by
this problem approx 2-3 ago also.
Best regards
Jan
