Q: Why do I see the error “Attempt to invoke interface method... on a null object reference” when trying to approve a leave request?
A: This technical error occurs because the employee does not have a sufficient leave balance remaining in the system. The system is trying to process a balance that doesn't exist (a "null" value). To fix it:
Check the Balance: Review the employee’s remaining leave days before attempting to approve.
Reject or Revise: Since the system cannot approve more days than are available, you must reject the request or ask the employee to revise it to match their actual balance.
Admin Adjustment: If the balance is incorrect, an Admin must update the employee's leave entitlement before the request can be approved.