We’re very sorry that you ran into these issues. We noticed that the latest update sites were redirecting to an older KNIME version for a couple of days, and I think that you might have run into those.
I just now took a fresh 5.8 and installed Geospatial as well as Image Processing (from the latest update site) and both worked like a charm.
Could you please try again? Sorry for the inconvenience.
Carsten