Arvados

We got the following report from one of our clusters:

Traceback (most recent call last):
  File "/usr/bin/arv-user-activity", line 8, in <module>
    sys.exit(main())
  File "/usr/share/python3/dist/python3-arvados-user-activity/lib/python3.7/site-packages/arvados_user_activity/main.py", line 219, in main
    getCollectionName(arv, e["properties"].get("collection_uuid"), e["properties"].get("portable_data_hash")),
  File "/usr/share/python3/dist/python3-arvados-user-activity/lib/python3.7/site-packages/arvados_user_activity/main.py", line 101, in getCollectionName
    if len(uuid) != 27:
TypeError: object of type 'NoneType' has no len()