New Windows 10 Computer not reading external drive in LR

I use an external USB drive for my LR catalogs, cache, previews and the image files themselves.  I also export JPG files there.  When I recently got a new notebook computer, I was able to read the HD fine and worked with LR.

After going back to my original computer again.  I again opened the files in the new one.  Back to the original and now the catalog won't open for an "unexpected error".  I've had this before and made sure the drives have EVERYONE set to full access in all folders.  I also tried creating a new user with my computer sign in.  I tried running LR as an Administrator.  No go.

I had to copy the catalog file from my backup drive to my working drive.  That opened LR but some of the images are damaged now.  I reimported them from the backup drive after deleting the original images from LR and the HD.  I'm still having problems when I create a TIF file to export to NIK Collection and then go back to LR.  When I try to export a JPG file, I get a "File seems to be unsupported or damaged" message.  Even though I again deleted the TIF files and redid the NIK changes to them.

I'm using Windows 10 machines, which should be up to date, with PS and LR also updated through Creative Cloud.