fix: just set the area if it is not set

Author: DanielRuf

app/code/Magento/Email/Model/AbstractTemplate.php

@@ -534,10 +534,9 @@ protected function cancelDesignConfig()
      */
     public function setForcedArea($templateId)
     {
-        if ($this->area) {
-            throw new \LogicException(__('Area is already set'));
+        if (!isset($this->area)) {
+            $this->area = $this->emailConfig->getTemplateArea($templateId);
         }
-        $this->area = $this->emailConfig->getTemplateArea($templateId);
         return $this;
     }
 

app/code/Magento/Theme/Model/Design/Config/Validator.php

@@ -114,6 +114,7 @@ private function getTemplateText($templateId, DesignConfigInterface $designConfi
         if (is_numeric($templateId)) {
             $template->load($templateId);
         } else {
+            $template->setForcedArea($templateId);
             $template->loadDefault($templateId);
         }
         $text = $template->getTemplateText();