'Periodic workspace save.' has encountered a problem


I'm repeatedly getting the above error message. the second line states: 'could not write metadata for ./workflowname ' . further details state that it could not write metadata for  .\workflowname\markers.snap because the system could not find the path specified.

This 'workflowname' is an old workflow that I have deleted ages ago. Any idea how I can stop with error message from appearing?

Many thanks in advance for your help!