The most common error a vending machine has is an understock error: error 34. A customer will see a greyed out product and be unable to select it for purchase. If there is product in the slot the customer wants to select, this can make them upset and hurt business. This guide will walk through what causes understock errors as well as how to fix them.

To check if a machine currently has any understock errors and clear out any that exist, follow these steps:

1. Log in to the admin login of the machine.
2. 1. Tap the arrow to the left of "Admin Login", then type password into the box below.
      
      
3. Tap the Goods Management option.
   
   
4. Tap the Replenishment option.
   
   
5. A screen will appear showing each slot, its current stock and capacity, and its error status.
6. 1. Any slot highlighted red is experiencing an error. The bottom of the slot will show what type of error.
      
      
7. Tap the Clear Fault button on the top left of the screen. This will clear out all slot faults for every slot in the machine, including the understock error.
8. 1. Note: Pressing the Clear Fault button will remove the fault code on the bottom of each slot, but not initially remove the red highlight. If this screen is exited and re-entered, the slots will no longer appear red. This is a known bug in the software, but does not affect any machine functionality.
      
      
9. Close the machine and scroll though all slots on the main shopping page to ensure none remain greyed out and inaccessible to customers.