diff --git a/app/api/missions/mission-created/route.ts b/app/api/missions/mission-created/route.ts
index d61f49f..c5403be 100644
--- a/app/api/missions/mission-created/route.ts
+++ b/app/api/missions/mission-created/route.ts
@@ -126,27 +126,27 @@ export async function POST(request: Request) {
     } = {};
     
     // Mapper les champs N8N vers notre schéma Prisma
+    // Vérifier que les valeurs ne sont pas des chaînes vides
     if (body.gitRepoUrl !== undefined) {
-      updateData.giteaRepositoryUrl = body.gitRepoUrl || null;
-      logger.debug('Updating giteaRepositoryUrl', { hasUrl: !!body.gitRepoUrl });
+      updateData.giteaRepositoryUrl = (body.gitRepoUrl && body.gitRepoUrl.trim() !== '') ? body.gitRepoUrl : null;
+      logger.debug('Updating giteaRepositoryUrl', { hasUrl: !!updateData.giteaRepositoryUrl, value: body.gitRepoUrl });
     }
     
     if (body.leantimeProjectId !== undefined) {
       // N8N peut retourner un number, on le convertit en string
-      updateData.leantimeProjectId = body.leantimeProjectId 
-        ? String(body.leantimeProjectId) 
-        : null;
-      logger.debug('Updating leantimeProjectId', { hasId: !!updateData.leantimeProjectId });
+      const projectId = body.leantimeProjectId ? String(body.leantimeProjectId).trim() : '';
+      updateData.leantimeProjectId = projectId !== '' ? projectId : null;
+      logger.debug('Updating leantimeProjectId', { hasId: !!updateData.leantimeProjectId, value: body.leantimeProjectId });
     }
     
     if (body.documentationCollectionId !== undefined) {
-      updateData.outlineCollectionId = body.documentationCollectionId || null;
-      logger.debug('Updating outlineCollectionId', { hasId: !!updateData.outlineCollectionId });
+      updateData.outlineCollectionId = (body.documentationCollectionId && body.documentationCollectionId.trim() !== '') ? body.documentationCollectionId : null;
+      logger.debug('Updating outlineCollectionId', { hasId: !!updateData.outlineCollectionId, value: body.documentationCollectionId });
     }
     
     if (body.rocketchatChannelId !== undefined) {
-      updateData.rocketChatChannelId = body.rocketchatChannelId || null;
-      logger.debug('Updating rocketChatChannelId', { hasId: !!updateData.rocketChatChannelId });
+      updateData.rocketChatChannelId = (body.rocketchatChannelId && body.rocketchatChannelId.trim() !== '') ? body.rocketchatChannelId : null;
+      logger.debug('Updating rocketChatChannelId', { hasId: !!updateData.rocketChatChannelId, value: body.rocketchatChannelId });
     }
     
     // Vérifier qu'il y a au moins un champ à mettre à jour
diff --git a/app/mission-tab/[missionId]/page.tsx b/app/mission-tab/[missionId]/page.tsx
index c9a1dc5..8e854b3 100644
--- a/app/mission-tab/[missionId]/page.tsx
+++ b/app/mission-tab/[missionId]/page.tsx
@@ -384,11 +384,14 @@ export default function MissionTabDetailPage() {
           )}
 
           {/* Ressources Métiers */}
-          {(mission.rocketChatChannelId || mission.outlineCollectionId || mission.giteaRepositoryUrl || mission.leantimeProjectId) && (
+          {((mission.rocketChatChannelId && mission.rocketChatChannelId.trim() !== '') || 
+            (mission.outlineCollectionId && mission.outlineCollectionId.trim() !== '') || 
+            (mission.giteaRepositoryUrl && mission.giteaRepositoryUrl.trim() !== '') || 
+            (mission.leantimeProjectId && mission.leantimeProjectId.toString().trim() !== '')) && (
             <div className="bg-white rounded-lg shadow-sm border border-gray-100 p-6">
               <h2 className="text-lg font-semibold text-gray-900 mb-4">Ressources Métiers</h2>
               <div className="space-y-3">
-                {mission.rocketChatChannelId && (() => {
+                {mission.rocketChatChannelId && mission.rocketChatChannelId.trim() !== '' && (() => {
                   // Build RocketChat URL: parole.slm-lab.net/channel/[channelId]
                   // If it's already a full URL, use it; otherwise build from ID
                   const rocketChatUrl = mission.rocketChatChannelId.startsWith('http') 
@@ -413,7 +416,7 @@ export default function MissionTabDetailPage() {
                   );
                 })()}
                 
-                {mission.outlineCollectionId && (() => {
+                {mission.outlineCollectionId && mission.outlineCollectionId.trim() !== '' && (() => {
                   // Build Outline URL: chapitre.slm-lab.net/collection/[collectionId]
                   // If it's already a full URL, use it; otherwise build from ID
                   const outlineUrl = mission.outlineCollectionId.startsWith('http') 
@@ -438,7 +441,7 @@ export default function MissionTabDetailPage() {
                   );
                 })()}
                 
-                {mission.giteaRepositoryUrl && (() => {
+                {mission.giteaRepositoryUrl && mission.giteaRepositoryUrl.trim() !== '' && (() => {
                   // Use mission name (sanitized) as repo name
                   const repoName = sanitizeMissionName(mission.name);
                   
@@ -469,7 +472,7 @@ export default function MissionTabDetailPage() {
                   );
                 })()}
                 
-                {mission.leantimeProjectId && (() => {
+                {mission.leantimeProjectId && mission.leantimeProjectId.toString().trim() !== '' && (() => {
                   // Build Leantime URL: agilite.slm-lab.net/projects/showProject/[projectId]
                   // If it's already a full URL, use it; otherwise build from ID
                   const leantimeUrl = mission.leantimeProjectId.startsWith('http') 
diff --git a/app/missions/[missionId]/page.tsx b/app/missions/[missionId]/page.tsx
index 55fcd77..7286988 100644
--- a/app/missions/[missionId]/page.tsx
+++ b/app/missions/[missionId]/page.tsx
@@ -18,7 +18,8 @@ import {
   Loader2,
   FileText,
   Lock,
-  CheckCircle
+  CheckCircle,
+  ArrowLeft
 } from "lucide-react";
 import { useToast } from "@/components/ui/use-toast";
 import { useParams, useRouter } from "next/navigation";
@@ -396,6 +397,18 @@ export default function MissionDetailPage() {
 
   return (
     <div className="bg-gray-50 min-h-screen p-6">
+      {/* Back Button */}
+      <div className="mb-4">
+        <Button 
+          variant="ghost" 
+          className="flex items-center text-gray-600 hover:text-gray-900"
+          onClick={() => router.push('/missions')}
+        >
+          <ArrowLeft className="mr-2 h-4 w-4" />
+          Retour aux missions
+        </Button>
+      </div>
+      
       {/* Header with Name and Logo */}
       <div className="bg-white rounded-lg shadow-sm border border-gray-100 mb-6 p-6">
         <div className="flex justify-between items-start">
@@ -591,11 +604,14 @@ export default function MissionDetailPage() {
           )}
 
           {/* Ressources Métiers */}
-          {(mission.rocketChatChannelId || mission.outlineCollectionId || mission.giteaRepositoryUrl || mission.leantimeProjectId) && (
+          {((mission.rocketChatChannelId && mission.rocketChatChannelId.trim() !== '') || 
+            (mission.outlineCollectionId && mission.outlineCollectionId.trim() !== '') || 
+            (mission.giteaRepositoryUrl && mission.giteaRepositoryUrl.trim() !== '') || 
+            (mission.leantimeProjectId && mission.leantimeProjectId.toString().trim() !== '')) && (
             <div className="bg-white rounded-lg shadow-sm border border-gray-100 p-6">
               <h2 className="text-xl font-semibold text-gray-800 mb-4">Ressources Métiers</h2>
               <div className="space-y-3">
-                {mission.rocketChatChannelId && (() => {
+                {mission.rocketChatChannelId && mission.rocketChatChannelId.trim() !== '' && (() => {
                   // Build RocketChat URL: parole.slm-lab.net/channel/[channelId]
                   // If it's already a full URL, use it; otherwise build from ID
                   const rocketChatUrl = mission.rocketChatChannelId.startsWith('http') 
@@ -620,7 +636,7 @@ export default function MissionDetailPage() {
                   );
                 })()}
                 
-                {mission.outlineCollectionId && (() => {
+                {mission.outlineCollectionId && mission.outlineCollectionId.trim() !== '' && (() => {
                   // Build Outline URL: chapitre.slm-lab.net/collection/[collectionId]
                   // If it's already a full URL, use it; otherwise build from ID
                   const outlineUrl = mission.outlineCollectionId.startsWith('http') 
@@ -645,7 +661,7 @@ export default function MissionDetailPage() {
                   );
                 })()}
                 
-                {mission.giteaRepositoryUrl && (() => {
+                {mission.giteaRepositoryUrl && mission.giteaRepositoryUrl.trim() !== '' && (() => {
                   // Use mission name (sanitized) as repo name
                   const repoName = sanitizeMissionName(mission.name);
                   
@@ -676,7 +692,7 @@ export default function MissionDetailPage() {
                   );
                 })()}
                 
-                {mission.leantimeProjectId && (() => {
+                {mission.leantimeProjectId && mission.leantimeProjectId.toString().trim() !== '' && (() => {
                   // Build Leantime URL: agilite.slm-lab.net/projects/showProject/[projectId]
                   // If it's already a full URL, use it; otherwise build from ID
                   const leantimeUrl = mission.leantimeProjectId.startsWith('http') 
diff --git a/app/missions/equipe/page.tsx b/app/missions/equipe/page.tsx
index 127b3f1..a2df439 100644
--- a/app/missions/equipe/page.tsx
+++ b/app/missions/equipe/page.tsx
@@ -769,14 +769,15 @@ export default function EquipePage() {
                         <td className="px-4 py-3 text-sm text-gray-600">{user.email}</td>
                         <td className="px-4 py-3">
                           <div className="flex flex-wrap gap-1">
-                            {(user.roles || []).slice(0, 3).map(role => (
-                              <span key={role} className="px-2 py-0.5 text-xs bg-blue-50 text-blue-700 rounded-full">
-                                {role}
-                              </span>
-                            ))}
-                            {(user.roles || []).length > 3 && (
-                              <span className="px-2 py-0.5 text-xs bg-gray-100 text-gray-600 rounded-full">
-                                +{user.roles.length - 3}
+                            {Array.isArray(user.roles) && user.roles.length > 0 ? (
+                              user.roles.map(role => (
+                                <span key={role} className="px-2 py-0.5 text-xs bg-blue-50 text-blue-700 rounded-full">
+                                  {role}
+                                </span>
+                              ))
+                            ) : (
+                              <span className="px-2 py-0.5 text-xs bg-gray-100 text-gray-400 rounded-full">
+                                Aucun rôle
                               </span>
                             )}
                           </div>
diff --git a/components/missions/mission-members-panel.tsx b/components/missions/mission-members-panel.tsx
index c86a1f6..f97b28f 100644
--- a/components/missions/mission-members-panel.tsx
+++ b/components/missions/mission-members-panel.tsx
@@ -481,15 +481,21 @@ export function MissionMembersPanel({
                 {selectedTab === 'users' ? (
                   filteredUsers.length > 0 ? (
                     <div className="divide-y divide-gray-200">
-                      {filteredUsers.map(user => (
+                      {filteredUsers.map(user => {
+                        const displayName = (user.firstName && user.lastName) 
+                          ? `${user.firstName} ${user.lastName}`
+                          : user.firstName || user.lastName || user.username || user.email || 'Utilisateur';
+                        const initials = (user.firstName?.[0] || "") + (user.lastName?.[0] || "") || user.username?.[0]?.toUpperCase() || user.email?.[0]?.toUpperCase() || "?";
+                        
+                        return (
                         <div key={user.id} className="p-3 hover:bg-gray-50 flex items-center justify-between">
                           <div className="flex items-center">
                             <div className="h-10 w-10 rounded-full bg-gray-100 flex items-center justify-center text-gray-600 font-medium mr-3">
-                              {user.firstName?.[0] || ""}{user.lastName?.[0] || ""}
+                              {initials}
                             </div>
                             <div>
-                              <div className="font-medium text-gray-900">{user.firstName} {user.lastName}</div>
-                              <div className="text-sm text-gray-500">{user.email}</div>
+                              <div className="font-medium text-gray-900">{displayName}</div>
+                              <div className="text-sm text-gray-500">{user.email || user.username || ''}</div>
                               {isUserAssigned(user.id) && (
                                 <div className="flex flex-wrap gap-1 mt-1">
                                   {getUserRoles(user.id).map((role) => (
@@ -570,7 +576,8 @@ export function MissionMembersPanel({
                             )}
                           </div>
                         </div>
-                      ))}
+                        );
+                      })}
                     </div>
                   ) : (
                     <div className="p-4 text-center text-gray-500">