Python Exception Occurred

Traceback (most recent call last):
  File "/usr/local/viewcvs-0.9.2/lib/viewcvs.py", line 2700, in run_cgi
    main()
  File "/usr/local/viewcvs-0.9.2/lib/viewcvs.py", line 2664, in main
    view_checkout(request)
  File "/usr/local/viewcvs-0.9.2/lib/viewcvs.py", line 1989, in view_checkout
    markup_stream(request, fp, revision, request.mime_type)
  File "/usr/local/viewcvs-0.9.2/lib/viewcvs.py", line 679, in markup_stream
    entry = rev_map[revision]
KeyError: '3.17'