From 420ee15759b7cfee8f78fc336844c6658fa8f7bf Mon Sep 17 00:00:00 2001
From: Thomas Kaul <4159106+dtslvr@users.noreply.github.com>
Date: Tue, 14 Jul 2026 19:23:48 +0200
Subject: [PATCH 1/3] Improve error handling

---
 .../middlewares/html-template.middleware.ts   | 35 ++++++++++++-------
 1 file changed, 22 insertions(+), 13 deletions(-)

diff --git a/apps/api/src/middlewares/html-template.middleware.ts b/apps/api/src/middlewares/html-template.middleware.ts
index 325f64eaa..607dfe41d 100644
--- a/apps/api/src/middlewares/html-template.middleware.ts
+++ b/apps/api/src/middlewares/html-template.middleware.ts
@@ -97,20 +97,29 @@ export class HtmlTemplateMiddleware implements NestMiddleware {
   private indexHtmlMap: { [languageCode: string]: string } = {};
 
   public constructor(private readonly i18nService: I18nService) {
-    try {
-      this.indexHtmlMap = SUPPORTED_LANGUAGE_CODES.reduce(
-        (map, languageCode) => ({
-          ...map,
-          [languageCode]: readFileSync(
-            join(__dirname, '..', 'client', languageCode, 'index.html'),
-            'utf8'
-          )
-        }),
-        {}
-      );
-    } catch (error) {
-      this.logger.error('Failed to initialize index HTML map', error);
+    if (!environment.production) {
+      return;
     }
+
+    this.indexHtmlMap = SUPPORTED_LANGUAGE_CODES.reduce((map, languageCode) => {
+      const indexHtmlPath = join(
+        __dirname,
+        '..',
+        'client',
+        languageCode,
+        'index.html'
+      );
+
+      try {
+        map[languageCode] = readFileSync(indexHtmlPath, 'utf8');
+      } catch {
+        this.logger.warn(
+          `Skipping language '${languageCode}': ${indexHtmlPath} not found`
+        );
+      }
+
+      return map;
+    }, {});
   }
 
   public use(request: Request, response: Response, next: NextFunction) {

From edbbb0a4632bf52118faeb50b59dd3a3ddd621c8 Mon Sep 17 00:00:00 2001
From: Thomas Kaul <4159106+dtslvr@users.noreply.github.com>
Date: Tue, 14 Jul 2026 19:24:09 +0200
Subject: [PATCH 2/3] Update changelog

---
 CHANGELOG.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2c3caf990..5e8fe76ca 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Set the change detection strategy to `OnPush` in the registration page
 - Set the change detection strategy to `OnPush` in the resources pages
 
+### Fixed
+
+- Improved the error handling in the `HtmlTemplateMiddleware`
+
 ## 3.26.0 - 2026-07-14
 
 ### Added

From 2f635387da73b774e11bcb292047b5eeffadcacd Mon Sep 17 00:00:00 2001
From: Thomas Kaul <4159106+dtslvr@users.noreply.github.com>
Date: Tue, 14 Jul 2026 19:28:54 +0200
Subject: [PATCH 3/3] Improve error handling

---
 apps/api/src/middlewares/html-template.middleware.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/apps/api/src/middlewares/html-template.middleware.ts b/apps/api/src/middlewares/html-template.middleware.ts
index 607dfe41d..bdace3402 100644
--- a/apps/api/src/middlewares/html-template.middleware.ts
+++ b/apps/api/src/middlewares/html-template.middleware.ts
@@ -127,7 +127,8 @@ export class HtmlTemplateMiddleware implements NestMiddleware {
     let languageCode = path.substr(1, 2);
 
     if (
-      !(SUPPORTED_LANGUAGE_CODES as readonly string[]).includes(languageCode)
+      !(SUPPORTED_LANGUAGE_CODES as readonly string[]).includes(languageCode) ||
+      !this.indexHtmlMap[languageCode]
     ) {
       languageCode = DEFAULT_LANGUAGE_CODE;
     }