diff --git a/app/api/missions/route.ts b/app/api/missions/route.ts
index 8fdde8ca..cb9e211b 100644
--- a/app/api/missions/route.ts
+++ b/app/api/missions/route.ts
@@ -140,6 +140,19 @@ export async function POST(request: Request) {
       }, { status: 400 });
     }
 
+    // Verify that the creator exists
+    const creator = await prisma.user.findUnique({
+      where: { id: userId }
+    });
+
+    if (!creator) {
+      return NextResponse.json({ 
+        error: 'Invalid creator ID', 
+        details: 'The specified creator does not exist',
+        code: 'INVALID_CREATOR'
+      }, { status: 400 });
+    }
+
     // Check if mission with same name exists
     const existingMission = await prisma.mission.findFirst({
       where: { name: body.name }
@@ -208,10 +221,11 @@ export async function POST(request: Request) {
 
         return NextResponse.json(workflowResult);
       } catch (error) {
+        console.error('Error triggering n8n workflow:', error);
         return NextResponse.json(
           { 
             error: 'Failed to create mission resources', 
-            details: 'The mission creation process failed. Please try again later.',
+            details: error instanceof Error ? error.message : 'The mission creation process failed. Please try again later.',
             code: 'WORKFLOW_ERROR'
           },
           { status: 500 }
@@ -220,69 +234,89 @@ export async function POST(request: Request) {
     }
 
     // Create mission directly (n8n request)
-    const mission = await prisma.mission.create({
-      data: {
-        name: body.name,
-        oddScope: body.oddScope || ['default'],
-        niveau: body.niveau,
-        intention: body.intention,
-        missionType: body.missionType,
-        donneurDOrdre: body.donneurDOrdre,
-        projection: body.projection,
-        services: Array.isArray(body.services) ? body.services.filter(Boolean) : [],
-        profils: Array.isArray(body.profils) ? body.profils.filter(Boolean) : [],
-        participation: body.participation || 'default',
-        creatorId: userId,
-        logo: body.logo || null,
-        leantimeProjectId: body.leantimeProjectId || null,
-        outlineCollectionId: body.documentationCollectionId || null,
-        rocketChatChannelId: body.rocketchatChannelId || null,
-        giteaRepositoryUrl: body.gitRepoUrl || null,
-        penpotProjectId: body.penpotProjectId || null
-      } as Prisma.MissionUncheckedCreateInput
-    });
+    try {
+      const mission = await prisma.mission.create({
+        data: {
+          name: body.name,
+          oddScope: body.oddScope || ['default'],
+          niveau: body.niveau,
+          intention: body.intention,
+          missionType: body.missionType,
+          donneurDOrdre: body.donneurDOrdre,
+          projection: body.projection,
+          services: Array.isArray(body.services) ? body.services.filter(Boolean) : [],
+          profils: Array.isArray(body.profils) ? body.profils.filter(Boolean) : [],
+          participation: body.participation || 'default',
+          creatorId: userId,
+          logo: body.logo || null,
+          leantimeProjectId: body.leantimeProjectId || null,
+          outlineCollectionId: body.documentationCollectionId || null,
+          rocketChatChannelId: body.rocketchatChannelId || null,
+          giteaRepositoryUrl: body.gitRepoUrl || null,
+          penpotProjectId: body.penpotProjectId || null
+        } as Prisma.MissionUncheckedCreateInput
+      });
 
-    // Add guardians and volunteers
-    if (body.guardians || body.volunteers) {
-      const missionUsers: MissionUserInput[] = [];
+      // Add guardians and volunteers
+      if (body.guardians || body.volunteers) {
+        const missionUsers: MissionUserInput[] = [];
 
-      // Add guardians
-      if (body.guardians) {
-        Object.entries(body.guardians).forEach(([role, userId]) => {
-          if (userId) {
-            missionUsers.push({
-              role,
-              userId: userId as string,
-              missionId: mission.id
-            });
-          }
-        });
+        // Add guardians
+        if (body.guardians) {
+          Object.entries(body.guardians).forEach(([role, userId]) => {
+            if (userId) {
+              missionUsers.push({
+                role,
+                userId: userId as string,
+                missionId: mission.id
+              });
+            }
+          });
+        }
+
+        // Add volunteers
+        if (body.volunteers && Array.isArray(body.volunteers)) {
+          body.volunteers.forEach(userId => {
+            if (userId) {
+              missionUsers.push({
+                role: 'volontaire',
+                userId,
+                missionId: mission.id
+              });
+            }
+          });
+        }
+
+        if (missionUsers.length > 0) {
+          await prisma.missionUser.createMany({
+            data: missionUsers
+          });
+        }
       }
 
-      // Add volunteers
-      if (body.volunteers && Array.isArray(body.volunteers)) {
-        body.volunteers.forEach(userId => {
-          if (userId) {
-            missionUsers.push({
-              role: 'volontaire',
-              userId,
-              missionId: mission.id
-            });
-          }
-        });
-      }
-
-      if (missionUsers.length > 0) {
-        await prisma.missionUser.createMany({
-          data: missionUsers
-        });
+      return NextResponse.json({
+        message: 'Mission created successfully',
+        mission
+      });
+    } catch (error) {
+      console.error('Error creating mission:', error);
+      if (error instanceof Prisma.PrismaClientKnownRequestError) {
+        if (error.code === 'P2003') {
+          return NextResponse.json({ 
+            error: 'Invalid reference', 
+            details: 'One or more referenced users do not exist',
+            code: 'INVALID_REFERENCE'
+          }, { status: 400 });
+        }
       }
+      return NextResponse.json(
+        { 
+          error: 'Failed to create mission', 
+          details: error instanceof Error ? error.message : String(error) 
+        },
+        { status: 500 }
+      );
     }
-
-    return NextResponse.json({
-      message: 'Mission created successfully',
-      mission
-    });
   } catch (error) {
     console.error('Error creating mission:', error);
     return NextResponse.json(