diff --git a/app/routers/ui.py b/app/routers/ui.py
index 123271b..1f23768 100644
--- a/app/routers/ui.py
+++ b/app/routers/ui.py
@@ -265,13 +265,25 @@ def job_detail(job_id: int, request: Request, db: Session = Depends(get_db)):
     job = db.query(PrintJob).filter(PrintJob.id == job_id).first()
     if not job:
         raise HTTPException(status_code=404, detail="Job not found")
-    stl = db.query(StlCache).filter_by(filename=job.file_name).first() if job.file_name else None
+
+    file_missing = False
+    stl = None
+    if job.file_name:
+        file_path = get_stl_dir() / job.file_name
+        if not file_path.exists():
+            file_missing = True
+        else:
+            stl = db.query(StlCache).filter_by(filename=job.file_name).first()
+            if stl is None and not job.file_name.endswith(".gcode"):
+                stl = analyse(job.file_name, db)
+
     estimation = estimate(stl.volume_ccm, job.job_material) if stl and stl.volume_ccm else None
     return templates.TemplateResponse("job_detail.html", {
         "request": request,
         "active": "jobs",
         "job": job,
         "stl": stl,
+        "file_missing": file_missing,
         "estimation": estimation,
         "printers": db.query(Printer).order_by(Printer.name).all(),
         "brackets": db.query(JobBracket).order_by(JobBracket.name).all(),
diff --git a/app/templates/job_detail.html b/app/templates/job_detail.html
index 776272a..21d93f3 100644
--- a/app/templates/job_detail.html
+++ b/app/templates/job_detail.html
@@ -103,7 +103,7 @@
     <div class="card h-100">
       <div class="card-header border-secondary d-flex align-items-center justify-content-between" style="border-color:#21262d">
         <span class="text-secondary small text-uppercase fw-normal">File &amp; Geometry</span>
-        {% if job.file_name %}
+        {% if job.file_name and not file_missing %}
         <div class="d-flex gap-2">
           <a href="/files/{{ job.file_name }}" class="btn btn-outline-primary btn-sm py-0 px-2" style="font-size:.75rem" download>
             <i class="bi bi-download me-1"></i>Download
@@ -122,7 +122,12 @@
         {% if job.file_name %}
         <div class="text-white mb-3 font-monospace" style="font-size:.85rem">{{ job.file_name }}</div>
         {% endif %}
-        {% if stl %}
+        {% if file_missing %}
+        <div class="alert alert-danger py-2 px-3 mb-0" style="font-size:.875rem">
+          <i class="bi bi-exclamation-triangle-fill me-2"></i>
+          File <code>{{ job.file_name }}</code> not found on disk.
+        </div>
+        {% elif stl %}
         <table class="table table-dark table-sm mb-0" style="font-size:.875rem">
           <tbody>
             <tr><td class="text-secondary border-0">Bounding box</td>
@@ -136,7 +141,7 @@
         {% elif job.file_name and job.file_name.endswith('.gcode') %}
         <p class="text-secondary small mb-0">Geometry not available for gcode files.</p>
         {% elif job.file_name %}
-        <p class="text-secondary small mb-0">Not yet analysed.</p>
+        <p class="text-secondary small mb-0">Analysis failed — check file format.</p>
         {% else %}
         <p class="text-secondary small mb-0">No file attached.</p>
         {% endif %}