The “Show Method if Not Applicable” option has been set to “Yes” as per the custom error message article but the error message is not being displayed.
With Shipping Override, “Show Method if not Applicable” shows the displayed error message when Shipping Override has suppressed all of the methods for a shipping carrier.
For example, if “Ground” is the only available shipping method selected in “Allowed Methods” for UPS and Shipping Override has suppressed it, as per our weight-based example #1, the error message will be displayed.
However, if shipping to another country, where “Ground” is not an available method, “Show Method if Not Applicable” will need to be set in
Shipping Methods -> UPS
The “Show Method if not Applicable for any Methods” is when Shipping Override has suppressed all of the available carriers. So, for example, if no shipping methods at all should be displayed for shipping Australia according to the Shipping Override CSV then the error message will be displayed in this scenario.