Adobe will no longer import or preview any film scans

Adobe was importing film scans fine until I upgraded to High Sierra on Mac.  The film negatives can fine and are visible everywhere else on the computer and using other programs. However, when I attempt to import them through Adobe Lightroom there are "no previews available." When I hit import it says there is an "unknown error"  I have seen other people with this problem but no solution anywhere on the internet.