Can you please check the Adobe Granite Monitor Handler in configManager (http://localhost:<port>/system/console/configMgr )?
And can you please check the error coming up in the error.log.
Or
Take snapshot of diskusage.sh configuration and delete it.
Refresh the page and recreate the property with the same values as the snapshot.
Re-create will pick the location of the factory scripts with default configuration.
Note : you may totally delete the factory configurations under "Adobe Granite Monitor Handler" if monitoring is not required at all.
Kautuk Sahni