pg_dump problems: [archiver (db)] query failed: ERROR: relation "pg_opfamily" does not exist

Hi,

While trying to move an old 8.1 Postgres install to a new server with
postgres 10.10, I get an error, listed hereunder:
I am trying to get a mydump_x_x_x.sql file to use to reinstall on the
target machine.

From my new machine I connect to my old machine like this:
erwin(at)ubuntu:~$  pg_dump -f "/home/erwin/mydump_$(date +%d_%m_%Y).sql"
-C -h somehost.com -p 5433 -U myvalidusername -d myremotedb
Password:
pg_dump: [archiver (db)] query failed: ERROR:  relation "pg_opfamily"
does not exist
pg_dump: [archiver (db)] query was: SELECT classid, objid, refclassid,
refobjid, deptype FROM pg_depend WHERE deptype != 'p' AND deptype != 'e'
UNION ALL
SELECT 'pg_opfamily'::regclass AS classid, amopfamily AS objid,
refclassid, refobjid, deptype FROM pg_depend d, pg_amop o WHERE deptype
NOT IN ('p', 'e', 'i') AND classid = 'pg_amop'::regclass AND objid =
o.oid AND NOT (refclassid = 'pg_opfamily'::regclass AND amopfamily =
refobjid)
UNION ALL
SELECT 'pg_opfamily'::regclass AS classid, amprocfamily AS objid,
refclassid, refobjid, deptype FROM pg_depend d, pg_amproc p WHERE
deptype NOT IN ('p', 'e', 'i') AND classid = 'pg_amproc'::regclass AND
objid = p.oid AND NOT (refclassid = 'pg_opfamily'::regclass AND
amprocfamily = refobjid)
ORDER BY 1,2

And no archive is created.

Does any of you kind people have advice? I am sure this worked on postgres9.

Regards,
Erwin Moller