The Dataflow appears to be stuck -- Serverless Data Analysis Lab 2c

Question

I'm working through the Coursera course "Serverless Data Analysis with Google BigQuery and Cloud Dataflow" and Lab 2c (and the previous lab) both fail to complete with the cryptic message

(bc5242b016f8bade): Workflow failed. Causes: (bc5242b016f8b199):
The  Dataflow appears to be stuck. Please reach out to the Dataflow team at
http://stackoverflow.com/questions/tagged/google-cloud-dataflow.

My Cloud Shell startup reads as follows. Note the SLF4J messages. The Job panel reports vCPU time and other statistics but the Step panels and Module dialog boxes show no information. I have tried removing the entire /training-data-analyst folder and recreating it and get the same problem.

    $ ./run_oncloud3.sh digital-modem-177923 digital-modem-177923 JavaProjectsThatNeedHelp
    project=digital-modem-177923  bucket=digital-modem-177923     main=com.google.cloud.training.dataanalyst.javahelp.JavaProjectsThatNeedHelp
    [INFO] Error stacktraces are turned on.
    [INFO] Scanning for projects...
    [INFO]
    [INFO] ----------------------------------------------------------------------
    [INFO] Building javahelp [1.0.0,2.0.0]
    [INFO] ----------------------------------------------------------------------
    [INFO]
    [INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ javahelp ---
    [WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
    [INFO] skip non existing resourceDirectory /home/mark_s_millman/training-data-analyst/courses/data_analysis/lab2/javahelp/src/main/resources
    [INFO]
    [INFO] --- maven-compiler-plugin:3.5.1:compile (default-compile) @ javahelp ---
    [INFO] Nothing to compile - all classes are up to date
    [INFO]
    [INFO] --- exec-maven-plugin:1.4.0:java (default-cli) @ javahelp ---
    SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
    SLF4J: Defaulting to no-operation (NOP) logger implementation
    SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
    Dataflow SDK version: 2.1.0
    Submitted job: 2017-09-05_18_28_22-5990977153508486146
    [INFO] ------------------------------------------------------------------------
    [INFO] BUILD SUCCESS
    [INFO] ------------------------------------------------------------------------
    [INFO] Total time: 12.304 s
    [INFO] Finished at: 2017-09-05T18:28:23-07:00
    [INFO] Final Memory: 34M/81M
    [INFO] ------------------------------------------------------------------------