diff --git a/controller/documentTemplate/DocumentTemplateController.js b/controller/documentTemplate/DocumentTemplateController.js
index 227c7ec..6c4550c 100644
--- a/controller/documentTemplate/DocumentTemplateController.js
+++ b/controller/documentTemplate/DocumentTemplateController.js
@@ -25,6 +25,7 @@ function saveDebugFile(filename, data, encoding = 'utf8') {
   const debugDir = ensureDebugDir();
   const p = path.join(debugDir, filename);
   try {
+    let folderStructureWarning = null;
     if (Buffer.isBuffer(data)) fs.writeFileSync(p, data);
     else fs.writeFileSync(p, data, { encoding });
     logger.debug(`[DEBUG] Wrote debug file: ${p}`);
@@ -1458,6 +1459,7 @@ exports.previewLatestForUser = async (req, res) => {
         const hasContractFolder = keys.some(k => k.startsWith(`${basePrefix}contract/`));
         const hasGdprFolder = keys.some(k => k.startsWith(`${basePrefix}gdpr/`));
         if (!hasContractFolder && !hasGdprFolder) {
+          folderStructureWarning = 'Admin user has to clean up and move the files in exoscale folder';
           logger.error('[previewLatestForUser] contract folder structure invalid: Admin user has to clean up and move the files in exoscale folder', {
             userId: targetUserId,
             contractCategory,
@@ -1470,6 +1472,11 @@ exports.previewLatestForUser = async (req, res) => {
       logger.warn('[previewLatestForUser] contract folder structure check failed', e && (e.stack || e.message));
     }
 
+    const jsonWithWarning = (payload) => {
+      if (!folderStructureWarning) return payload;
+      return { ...payload, warning: folderStructureWarning };
+    };
+
     // Choose document_type set based on contractType (aligned with ContractUploadService paths)
     // uploadContract stores under contracts/<category>/<userId>/<contract_type> with document_type 'contract'
     // so use contract_type column to disambiguate between contract vs gdpr
@@ -1502,7 +1509,8 @@ exports.previewLatestForUser = async (req, res) => {
     }
 
     if (!doc || !doc.object_storage_id) {
-      return res.status(404).json({ message: `No uploaded ${contractType.toUpperCase()} file found for this user` });
+      if (folderStructureWarning) res.setHeader('X-Contract-Preview-Warning', folderStructureWarning);
+      return res.status(404).json(jsonWithWarning({ message: `No uploaded ${contractType.toUpperCase()} file found for this user` }));
     }
 
     try {
@@ -1526,7 +1534,8 @@ exports.previewLatestForUser = async (req, res) => {
       const pdfBuffer = await s3BodyToBuffer(fileObj.Body);
       if (!pdfBuffer || !pdfBuffer.length) {
         logger.warn('[previewLatestForUser] S3 returned empty Body', { key: doc.object_storage_id, userId: targetUserId, contractType });
-        return res.status(404).json({ message: `${contractType.toUpperCase()} file not available` });
+        if (folderStructureWarning) res.setHeader('X-Contract-Preview-Warning', folderStructureWarning);
+        return res.status(404).json(jsonWithWarning({ message: `${contractType.toUpperCase()} file not available` }));
       }
 
       const b64 = pdfBuffer.toString('base64');
@@ -1537,14 +1546,17 @@ exports.previewLatestForUser = async (req, res) => {
         </body></html>
       `);
       res.setHeader('Content-Type', 'text/html; charset=utf-8');
+      if (folderStructureWarning) res.setHeader('X-Contract-Preview-Warning', folderStructureWarning);
       return res.send(html);
     } catch (e) {
       if (e && (e.name === 'NoSuchKey' || (e.$metadata && e.$metadata.httpStatusCode === 404))) {
         logger.warn('[previewLatestForUser] object missing in storage', { key: doc.object_storage_id, userId: targetUserId, contractType });
-        return res.status(404).json({ message: `${contractType.toUpperCase()} file not available` });
+        if (folderStructureWarning) res.setHeader('X-Contract-Preview-Warning', folderStructureWarning);
+        return res.status(404).json(jsonWithWarning({ message: `${contractType.toUpperCase()} file not available` }));
       }
       logger.error('[previewLatestForUser] S3 fetch failed', e && (e.stack || e.message));
-      return res.status(500).json({ message: 'Failed to load user document' });
+      if (folderStructureWarning) res.setHeader('X-Contract-Preview-Warning', folderStructureWarning);
+      return res.status(500).json(jsonWithWarning({ message: 'Failed to load user document' }));
     }
   } catch (err) {
     logger.error('[previewLatestForUser] error', err && err.stack ? err.stack : err);