hi @suseearun ,
I managed to reproduce the error on a fresh install of KNIME 5.2.4, that didn’t have the Continental Nodes installed on it.
So, I would say the solution is as I have suggested above → Make sure continental nodes are fully installed, restart KNIME and then re-download the demo workflow - Note don’t attempt to use the already-downloaded version since it will almost certainly now be irreparably “broken” as links will have been lost because nodes weren’t available when it was downloaded.