diff --git a/app/plugins/builtins/report_generator/routes.py b/app/plugins/builtins/report_generator/routes.py
index 002070f..c943711 100644
--- a/app/plugins/builtins/report_generator/routes.py
+++ b/app/plugins/builtins/report_generator/routes.py
@@ -15,7 +15,10 @@ from fastapi.responses import StreamingResponse
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.core.db import get_db
+from app.models.contact import Contact
+from app.models.audit import AuditLog
+
+from app.core.db import get_db, set_tenant_context
 from app.deps import get_current_user, require_permission
 from app.plugins.builtins.report_generator.models import (
     ReportInstance,
@@ -156,15 +159,100 @@ async def generate_preset(
     db: AsyncSession = Depends(get_db),
     current_user: dict = Depends(require_permission("reports:generate")),
 ):
-    """Generate a preset report by name (e.g. contact_list, calendar_week)."""
+    """Generate a preset report by name (e.g. contact_list, calendar_week).
+
+    Fetches live data from the database based on the preset type,
+    merges with user-provided parameters, and generates the report.
+    """
     tenant_id = uuid.UUID(current_user["tenant_id"])
     user_id = uuid.UUID(current_user["user_id"])
 
-    # Generate report first (no DB interaction during sync IO)
-    await db.close()
+    # Set tenant context for RLS
+    await set_tenant_context(db, tenant_id)
+
+    # Fetch data based on preset type
+    parameters = dict(body.parameters)  # copy user params
+
     try:
+        if body.preset == "contact_list":
+            # Fetch all contacts (type='person') for this tenant
+            q = select(Contact).where(
+                Contact.tenant_id == tenant_id,
+                Contact.type == "person",
+                Contact.deleted_at.is_(None),
+            ).order_by(Contact.displayname)
+            result = await db.execute(q)
+            contacts = result.scalars().all()
+            parameters["contacts"] = [
+                {
+                    "name": f"{c.firstname or ''} {c.surname or ''}".strip() or c.displayname or "",
+                    "email": c.email_1 or "",
+                    "phone": c.phone_1 or "",
+                    "type": c.type or "person",
+                    "company": "",  # contact persons are separate
+                }
+                for c in contacts
+            ]
+            parameters["title"] = parameters.get("title", "Kontaktliste")
+
+        elif body.preset == "company_list":
+            # Fetch all companies (type='company') for this tenant
+            q = select(Contact).where(
+                Contact.tenant_id == tenant_id,
+                Contact.type == "company",
+                Contact.deleted_at.is_(None),
+            ).order_by(Contact.name)
+            result = await db.execute(q)
+            companies = result.scalars().all()
+            parameters["companies"] = [
+                {
+                    "name": c.name or c.displayname or "",
+                    "address": (
+                        f"{c.mailing_street or ''} {c.mailing_number or ''}".strip()
+                        or f"{c.visit_street or ''} {c.visit_number or ''}".strip()
+                        or ""
+                    ),
+                    "zip": c.mailing_postalcode or "",
+                    "city": c.mailing_city or "",
+                    "phone": c.phone_1 or "",
+                    "email": c.email_1 or "",
+                    "contact_person": "",  # could be extended with ContactPerson lookup
+                }
+                for c in companies
+            ]
+            parameters["title"] = parameters.get("title", "Firmenliste")
+
+        elif body.preset == "audit_log":
+            # Fetch recent audit log entries for this tenant
+            q = select(AuditLog).where(
+                AuditLog.tenant_id == tenant_id,
+            ).order_by(AuditLog.timestamp.desc()).limit(500)
+            result = await db.execute(q)
+            entries = result.scalars().all()
+            parameters["entries"] = [
+                {
+                    "timestamp": str(e.timestamp) if e.timestamp else "",
+                    "user": str(e.user_id) if e.user_id else "—",
+                    "action": e.action or "",
+                    "entity": e.entity_type or "",
+                    "entity_id": str(e.entity_id) if e.entity_id else "",
+                    "details": str(e.changes) if e.changes else "",
+                }
+                for e in entries
+            ]
+            parameters["title"] = parameters.get("title", "Audit-Log")
+
+        elif body.preset in ("calendar_week", "calendar_month"):
+            # Calendar presets: pass user params through (no DB model yet)
+            parameters.setdefault("title", "Wochenkalender" if body.preset == "calendar_week" else "Monatskalender")
+            parameters.setdefault("days", [])
+            parameters.setdefault("hours", [])
+            parameters.setdefault("weeks", [])
+            parameters.setdefault("weekday_names", [])
+
+        # Generate report
         file_bytes, ext = generate_preset_report(
-            body.preset, body.output_format, body.parameters
+            body.preset, body.output_format, parameters
         )
     except Exception as exc:
         raise HTTPException(
@@ -175,7 +263,7 @@ async def generate_preset(
             },
         ) from exc
 
-    # Return file directly as streaming response (avoid DB tracking due to greenlet issues in test env)
+    # Return file directly as streaming response
     import io as _io
 
     media_types = {
diff --git a/frontend/src/components/workflows/WorkflowEditor.tsx b/frontend/src/components/workflows/WorkflowEditor.tsx
index 1f58465..e52bfc9 100644
--- a/frontend/src/components/workflows/WorkflowEditor.tsx
+++ b/frontend/src/components/workflows/WorkflowEditor.tsx
@@ -131,6 +131,11 @@ export function WorkflowEditor({ open, workflow, onClose }: WorkflowEditorProps)
       return;
     }
 
+    if (form.steps.length === 0) {
+      toast.error('Mindestens ein Schritt ist erforderlich');
+      return;
+    }
+
     const hasEmptyStepName = form.steps.some((s) => !s.name.trim());
     if (hasEmptyStepName) {
       toast.error('Alle Schritte muessen einen Namen haben');
@@ -161,7 +166,17 @@ export function WorkflowEditor({ open, workflow, onClose }: WorkflowEditorProps)
       }
       onClose();
     } catch (err: any) {
-      toast.error(err.message || 'Fehler beim Speichern');
+      // Show detailed validation errors from backend (422)
+      if (err.validationErrors) {
+        const details = Object.entries(err.validationErrors)
+          .map(([field, msgs]) => `${field}: ${msgs.join(', ')}`)
+          .join('; ');
+        toast.error(`Validierungsfehler: ${details}`);
+      } else if (err.detail) {
+        toast.error(err.detail);
+      } else {
+        toast.error(err.message || 'Fehler beim Speichern');
+      }
     }
   };