As I could not find any information about this error when I faced it this is just a short hint: If you try to use pg_dump or pg_dumpall out of a PPAS installation to dump or dumpall a community version of PostgreSQL you probably get this:

pg_dump: [archiver (db)] query failed: ERROR: schema "sys" does not exist
pg_dump: [archiver (db)] query was: SET search_path = pg_catalog, sys, dbo

The solution is quite easy but you have to be aware of: The pg_dump and pg_dumpall utilities shipped with PPAS are not compatible with community PostgreSQL and therefore you’ll have to install the PostgreSQL community binaries and use the utilities from there to succeed (even if PPAS is installed in PostgreSQL mode).