KSTAR Memo 6 kVA Errors code 26 & 34

KSTAR Memo 6 kVA with only three buttons:
🔘 Up/Return (⟳)
🔘 Off
🔘 On

UPS is a KSTAR Memo 6 kVA (4.8 kW) model. Based on that label:

Input: 220 V AC, 50/60 Hz, max 40 A (single-phase)

Output: 220 V AC, 50/60 Hz, 25 A (single-phase)

Battery system: ±120 V DC (which usually means a 20-battery setup using 12 V batteries — 10 in each string)

Protection class: I

Icc: 10 kA fault current rating

Code 34 means only UPS battery fault machine is ok..The problem will be solved if you change the battery.

Code 26 means battery setting error. UPS has 20 batteries, but in the function menu, somehow it's changed & showing 16 battery system. That's why it shows an error. After changing the battery quantity, the problem is solved. Details are in the attached videos.