ORA-26536: refresh was aborted because of

admin

ORA-26536: refresh was aborted because of conflicts caused by deferred
transactions
Cause: There are outstandingconflicts logged in the DEFERROR table at the
materialized view's master site.
Action: Resolve the conflictsin the master DEFERROR table and refresh again
after the table is empty. Alternatively, refresh with REFRESH_AFTER_ERRORS,
even if there are conflicts in the master's DEFERROR table. Proceeding despite
conflicts can result in an updatable materialized view's changes appearing tobe
temporarily lost, until a refresh succeeds after the conflicts are resolved.