Hi there, thanks for posting. I haven’t seen this specific error before, but I have heard of issues with gpkg in ArcGIS. This thread offers some ideas of things that might cause this problem. Coastal Vulnerability: csv output looks good - gpkg output does not open in ArcGIS
Which file in particular were you trying to open? Or does this error occur for any of the gpkg files that the model created? Can you share one of the problematic gpkg files by uploading it here? Or by sharing a link?
Thanks,