The project description file (.project) for '...' is missing

I removed a number of old workflow groups from within Knime using the DELETE option of the right mouse click.  But now batch jobs are cluttering the log file with messages of missing project files for those old directories.  The problem seems to be in Eclipse but I can't find any instructions to clean it up.

Example:

 

!MESSAGE The project description file (.project) for 'compare' is missing.  This file contains important information about the project.  The project will not function properly until this file is restored.

Hi,

Each KNIME workflow / workflow group includes a ".project" file. Are your batch jobs in some way referencing the workflow groups you deleted?

Cheers,

Roland