its a bit broken

internal/api/metadata.go

@@ -38,7 +38,7 @@ func (s *Server) handleSubmitMetadata(w http.ResponseWriter, r *http.Request) {
 
 	var metadata types.BlendMetadata
 	if err := json.NewDecoder(r.Body).Decode(&metadata); err != nil {
-		s.respondError(w, http.StatusBadRequest, "Invalid metadata JSON")
+		s.respondError(w, http.StatusBadRequest, fmt.Sprintf("Invalid metadata JSON: %v", err))
 		return
 	}
 
@@ -230,7 +230,7 @@ func (s *Server) extractMetadataFromContext(jobID int64) (*types.BlendMetadata,
 	}
 
 	if blendFile == "" {
-		return nil, fmt.Errorf("no .blend file found in context")
+		return nil, fmt.Errorf("no .blend file found in context - the uploaded context archive must contain at least one .blend file for metadata extraction")
 	}
 
 	// Use embedded Python script