A Handlebars partial or helper is breaking a page, what causes it?

Usually a {{> }} partial path that points at a template that doesn’t exist, a custom helper that isn’t registered, or a malformed {{#each}} / {{#if}} block. BigCommerce will blank the region or fail the build with something like “The partial header/account could not be found”. We trace the error to the exact template, restore the correct partial or helper, and add a check so the region renders again.