Most likely the data-files are corrupt. I am not sure exactly where they are in such an old version, but they should be in $USER/.vnl/job-manager or something like that. Delete all of them except for machines.hdf5. You will lose information about running jobs, but your machine definitions will still be available. We re-designed the data-structure in T-2022.03 to avoid this problem, so I suggest upgrading to a newer version.
