gitlab:backup:create is failing with pg_dump: [archiver (db)] query failed: ERROR: permission denied for schema gitlabhq_production

Ubuntu: 16.x
Gitlab Omnibus CE version: 11.0.1
When i run the command gitlab-rake gitlab:backup:create, its failing with the error
Dumping PostgreSQL database gitlabhq_production … pg_dump: [archiver (db)] query failed: ERROR: permission denied for schema gitlabhq_production
pg_dump: [archiver (db)] query was: LOCK TABLE gitlabhq_production.abuse_reports IN ACCESS SHARE MODE
[FAILED]
rake aborted!
Backup::Error: Backup failed
/opt/gitlab/embedded/service/git


Could you please help us resolve it.