Quote Originally Posted by MagicMan View Post
I deleted all shipping zones accept US.
What exactly did you do to accomplish that?

Is this something you did inside the database?
Or some steps you followed in some article?
Or did you literally click Delete on every non-US zone in your Admin->Locations/Taxes->Zones screen?
Or something you did in Admin->Locations/Taxes->Zone Definitions?
Or something else?

Quote Originally Posted by MagicMan View Post
I would like to add Canada back.
Is Canada still in your store's list of countries?

And what Zen Cart version are you using? Since v1.5.2 there's a Status setting for each country to denote whether it should be usable by customers or not. It's better to use that instead of "deleting countries from the database".