ENGINE-16004 Exception while closing command context: ENGINE-02024 Expression '${RequistionRecruiters} ' didn't resolve to type 'Collection'

when I deploy camunda modeler and want to submit the task the below error occur can any one help me
error :
ENGINE-16004 Exception while closing command context: ENGINE-02024 Expression '${RequistionRecruiters} ’ didn’t resolve to type ‘Collection’

Hope it’s not misspelled.

Check whether the collection variable exists with global scope.

how can I check the scope ?
I upload my file, can you check the file ?HumanresWorkforce.bpmn (8.6 KB)