Duplicate value in Cell Address field
From Kolmisoft Wiki
If you see error Duplicate value in Cell Address field when editing any settings at SETTINGS -> Setup -> Settings, it means that you have duplicate values at SETTINGS -> Setup -> Settings -> Invoices -> XLSX.
To solve the issue, please go to SETTINGS -> Setup -> Settings -> Invoices -> XLSX and check for duplicate values, as shown in the picture below.
Please change the fields, so no duplicated would be present.