Unable to update Product Rate Plan - "Starting Unit of charge "Name" must bigger than last Ending Unit[#]"
When attempting to update the rate plan tier in a Volume Pricing model Rate Plan Charge, upon attempting to save the changes the following error message is displayed: Starting Unit of charge "Name" must bigger than last Ending Unit[#]. This is really confusing for customers because the starting unit is actually less than the last ending unit, even before the customer makes any changes. It is caused when Charge Model = Volume Pricing, the first tier is set to anything other than 0, and a new currency is enabled in Z-Billing settings.
This causes the system to append a new 0-start tier to the newly enabled currency. When attempting to go back and edit the original rate plan, the system generates a duplicate 0-start tier from the new currency in the original rate plan, causing the error.
Defect number: BIL-14235
Workaround: disable other currencies in Z-Billing settings, then update the charge or recreate the charge.