- Fixes rendering issue where DOMDocument throws a notice on unescaped

html entity

lib/Newsletter/Renderer/Renderer.php

@@ -92,12 +92,16 @@ class Renderer {
   }
 
   function postProcessTemplate($template) {
-    // replace all !important tags except for in the body tag
     $DOM = $this->DOM_parser->parseStr($template);
     $template = $DOM->query('.mailpoet_template');
+    // replace all !important tags except for in the body tag
     $template->html(
       str_replace('!important', '', $template->html())
     );
+    // encode ampersand
+    $template->html(
+      str_replace('&', '&', $template->html())
+    );
     $template = apply_filters(
       'mailpoet_rendering_post_process',
       $DOM->__toString()