Trouble saving KNIME workflow after >3 days without saving?

Recently we ran a very intense training procedure from within a KNIME workflow. The whole thing ran for roughly 4 days.

Finally terminated we ran into troubles saving the workflow, getting some ‘File access problems: /var/folders… etc. etc’ error dialog.

Turns out that Java cleans up its temp folder after 3 days or so (on MacOS at least). In doing so KNIME ended up having the open workflow being corrupted.

Way out: before starting such a monstrous run you might want to configure KNIME to use another temp folder… one that Java does not wipe out every now and then.

  • In KNIME open via menu: KNIME – Preferences
  • Then choose ‘KNIME’ on the left side, and
  • enter a folder name of your choice in the text field with the label ‘Directory for temporary files’.
  • Restart KNIME – done!