Lightroom CC 3.2 desktop will not export certain images

Hello all,

I have a set of DNG images that were imported into Lightroom desktop and then edited.  When I try to export these (17 images) as jpg's the export progress bar hangs indefinitely without exporting anything.  The images sync succefully and I can export them on mobile on my phone and ipad.

I have tried reinstalling lightroom and logging out and back into my CC account with to no avail.

I have had the same problem with jpg's that were imported into Lightroom.

I  have also tried turning harware acceleration on and off with no change.

My desktop is an:

iMac (Retina 5K, 27-inch, 2019)

3.6 GHz 8-Core Intel Core i9

72 GB 2667 MHz DDR4

Thanks for the help,

Joe