diff --git a/app/assets/javascripts/editor/editor.js.erb b/app/assets/javascripts/editor/editor.js.erb
index 9468bd85..a49a34b7 100644
--- a/app/assets/javascripts/editor/editor.js.erb
+++ b/app/assets/javascripts/editor/editor.js.erb
@@ -370,7 +370,8 @@ var CodeOceanEditor = {
     },
 
     initializeRegexes: function () {
-        this.regex_for_language.set("ace/mode/python", /File "(.+?)", line (\d+)/g);
+        // These RegEx are run on the HTML escaped output!
+        this.regex_for_language.set("ace/mode/python", /File "(.+?)", line (\d+)/g);
         this.regex_for_language.set("ace/mode/java", /(.*\.java):(\d+):/g);
     },
 
@@ -467,7 +468,7 @@ var CodeOceanEditor = {
             let errorMessagesToShow = [];
             result.error_messages.forEach(function (item) {
                 if (item) {
-                    errorMessagesToShow.push(item.replace(/\n/g, '<br>'))
+                    errorMessagesToShow.push(item)
                 }
             })
 
@@ -605,7 +606,8 @@ var CodeOceanEditor = {
         if (this.tracepositions_regex) {
             $('#output>pre').each($.proxy(function(index, element) {
                 element = $(element)
-                const text = element.text();
+                debugger;
+                const text = _.escape(element.text());
                 element.on("click", "a", this.jumpToSourceLine.bind(this));
 
                 let matches;
diff --git a/app/assets/stylesheets/editor.css.scss b/app/assets/stylesheets/editor.css.scss
index fcfa2d92..06adf57a 100644
--- a/app/assets/stylesheets/editor.css.scss
+++ b/app/assets/stylesheets/editor.css.scss
@@ -155,11 +155,13 @@ button i.fa-spin {
 .error_messages_list {
   list-style-type: disc;
   padding-inline-start: 1.25rem;
+  white-space: pre-wrap;
 }
 
 .single_error_message {
   list-style-type: none;
   padding-inline-start: 0;
+  white-space: pre-wrap;
 }
 
 .enforce-top-margin {