ERROR
REP-0004: Warning: Unable to open user preference file.
MSG-00001: (Import_purge 1) Check control table for the purge process
MSG-00001: (Check_control_table 1) Lock the control table
MSG-00003: (Check_control_table 2) Fetch import_requests
MSG-00007: (Check_control_table 5) Insert record into control table
MSG-00008: (Check_control_table 6) Commit
MSG-00002: (Import_purge 2) Updating Org Id to value if Operating Unit is not Null But Org Id is null
MSG-00003: (Import_purge ) Deleting records in interface tables…
MSG-00009: (Import_purge 6) Commit to the database
SOLUTION
Copy the prefs.ora file from your Reports Builder Home $ORACLE_HOME/tools/admin/ directory into the Oracle Home directory /home/oracle.
$ cp ORACLE_HOME/tools/admin/pref.ora /home/oracle/