actually create the 0% tax rate

(Still warn if tax rate is not filled at all)

src/pretix/control/forms/event.py

@@ -231,7 +231,7 @@ class EventWizardBasicsForm(I18nModelForm):
             raise ValidationError({
                 'timezone': _('Your default locale must be specified.')
             })
-        if not data.get("no_taxes") and not data.get("tax_rate"):
+        if not data.get("no_taxes") and data.get("tax_rate") is None:
             raise ValidationError({
                 'tax_rate': _('You have not specified a tax rate. If you do not want us to compute sales taxes, please '
                               'check "{field}" above.').format(field=self.fields["no_taxes"].label)

src/pretix/control/views/main.py

@@ -313,7 +313,7 @@ class EventWizard(SafeSessionWizardView):
                     )
                 event.set_defaults()
 
-            if basics_data['tax_rate']:
+            if basics_data['tax_rate'] is not None:
                 if not event.settings.tax_rate_default or event.settings.tax_rate_default.rate != basics_data['tax_rate']:
                     event.settings.tax_rate_default = event.tax_rules.create(
                         name=LazyI18nString.from_gettext(gettext('VAT')),