error recovering pg_dump compressed file
Just use pg_restore:


  pg_restore is a utility for restoring a PostgreSQL database from an
  archive created by pg_dump in one of the non-plain-text formats


Using -Z5 -Fc on pg_dump does not transform the backup into a gzip format. It adjusts the compression level, but the structure of the file is still the specific custom archive format that non-database commands like gzip or 7zip don't know.