Canada Post "-4004 Item is too large to be packed"

[swguy]

Canada Post seems to be saying "-4004 Item is too large to be packed." a lot even with two small items in the cart. Anyone else seeing this?

[Trinity14]

What are you using to communicate with Canada Post?
Have you developed the API or are you still able to use the Sell Online account?

From my experience, this error points to not having enough box dimensions for Canada Post to select.

Step 1. All products need to have shipping weight and dimensions - length, width, height. It is preferred to be in kgs and cm.

Step 2. The shipping module in admin needs to be installed and enabled (with the appropriate details) and it's own sort order.

Step 3. If using sellonline.canadapost.ca , click on modify my profile. Select the Add/modify/delete boxes option. Add the new box with description. Save your changes. You may have to add several boxes to accommodate the varying product measurements and restrictions.