ZIP in checkout is already validation failed at page load

[svossen]

When I open the checkout page the ZIP code field is already validation failed. The field doesn't have a value. It doesn't occur every I open the checkout page.

I noticed this with two different Magento 2 environments. One is version 2.1.0, the other one is 2.0.7. It doesn't matter which theme I'm using, it occurs with the blank theme as well. I'm using Dutch locale.

[hieu_hidro]

That mean shipping address data is empty. 

You can check it on Magento_Checkout/js/view/shipping.js at line **103**
I have insert 
  

null != shippingAddressData.postcode

And this bug was fixed. Please make sure all case work.

if (shippingAddressData && null != shippingAddressData.postcode)