catch crashes when no data has been imported

core/views/uploads.py

@@ -515,8 +515,13 @@ def scanupload(request, path=None):
                     f = Path(settings.SURVEX_DATA) / svx
                     if f.is_file():
                         path = svx.parent / svx.stem
-                        #print(f' - {path=}')
-                        svxfile = SurvexFile.objects.get(path=path)
+                        #print(f' - {path=}')                          
+                        try:
+                            svxfile = SurvexFile.objects.get(path=path)
+                        except:
+                            message = f'Specified survex file not found - database apparently empty, you probably need to do a full re-import of all data.'
+                            return render(request, 'errors/generic.html', {'message': message})   
+                        
                         print(f' - {svxfile=}')
                         caves.append(svxfile.cave)
                         caverefs.append(svxfile.cave.reference())