Oracle Message QSM-00780 - the task string could not be executed because the workload string is being modified

ERRORthe task string could not be executed because the workload string is being modified
CAUSEWhile attempting to execute a task, Access Advisor checks for exclusive access to all of the referenced workloads. If any cannot be reserved, then the execution fails.
ACTIONWait until the referenced workloads are free for exclusive access retry the operation.