diff --git a/controller/documentTemplate/DocumentTemplateController.js b/controller/documentTemplate/DocumentTemplateController.js
index 6c4550c..bfa69d1 100644
--- a/controller/documentTemplate/DocumentTemplateController.js
+++ b/controller/documentTemplate/DocumentTemplateController.js
@@ -253,6 +253,19 @@ function streamToString(s3BodyStream, templateId) {
   });
 }
 
+function formatS3Error(err) {
+  if (!err) return null;
+  if (typeof err === 'string') return { message: err };
+  return {
+    name: err.name,
+    message: err.message,
+    code: err.code,
+    stack: err.stack,
+    metadata: err.$metadata,
+    cause: err.cause && (err.cause.message || err.cause)
+  };
+}
+
 // Ensure HTML is a valid document
 function ensureHtmlDocument(html) {
   // If it already looks like a full HTML doc, return as is
@@ -1410,6 +1423,8 @@ exports.previewLatestForUser = async (req, res) => {
   const allowedContractTypes = ['contract', 'gdpr'];
   const contractType = allowedContractTypes.includes(contractTypeParam) ? contractTypeParam : 'contract';
 
+  let folderStructureWarning = null;
+
   logger.info('[previewLatestForUser] start', { targetUserId, contractType, requestId: req.id });
 
   if (!req.user || !['admin', 'super_admin'].includes(req.user.role)) {
@@ -1514,7 +1529,7 @@ exports.previewLatestForUser = async (req, res) => {
     }
 
     try {
-      const s3File = sharedExoscaleClient || new S3Client({
+      const createClient = () => sharedExoscaleClient || new S3Client({
         region: process.env.EXOSCALE_REGION,
         endpoint: process.env.EXOSCALE_ENDPOINT,
         forcePathStyle: true,
@@ -1523,6 +1538,7 @@ exports.previewLatestForUser = async (req, res) => {
           secretAccessKey: process.env.EXOSCALE_SECRET_KEY
         }
       });
+      let s3File = createClient();
       logger.info('[previewLatestForUser] attempting S3 fetch', {
         bucket: process.env.EXOSCALE_BUCKET,
         key: doc.object_storage_id,
@@ -1530,7 +1546,27 @@ exports.previewLatestForUser = async (req, res) => {
         contractType
       });
       const cmd = new GetObjectCommand({ Bucket: process.env.EXOSCALE_BUCKET, Key: doc.object_storage_id });
-      const fileObj = await s3File.send(cmd);
+      let fileObj;
+      try {
+        fileObj = await s3File.send(cmd);
+      } catch (firstErr) {
+        logger.warn('[previewLatestForUser] S3 fetch failed (shared client), retrying with fresh client', {
+          key: doc.object_storage_id,
+          userId: targetUserId,
+          contractType,
+          error: formatS3Error(firstErr)
+        });
+        s3File = new S3Client({
+          region: process.env.EXOSCALE_REGION,
+          endpoint: process.env.EXOSCALE_ENDPOINT,
+          forcePathStyle: true,
+          credentials: {
+            accessKeyId: process.env.EXOSCALE_ACCESS_KEY,
+            secretAccessKey: process.env.EXOSCALE_SECRET_KEY
+          }
+        });
+        fileObj = await s3File.send(cmd);
+      }
       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 });
@@ -1554,7 +1590,12 @@ exports.previewLatestForUser = async (req, res) => {
         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));
+      logger.error('[previewLatestForUser] S3 fetch failed', {
+        key: doc.object_storage_id,
+        userId: targetUserId,
+        contractType,
+        error: formatS3Error(e)
+      });
       if (folderStructureWarning) res.setHeader('X-Contract-Preview-Warning', folderStructureWarning);
       return res.status(500).json(jsonWithWarning({ message: 'Failed to load user document' }));
     }