Why is my Configurator locking up when importing VPP codes?

I am running Configurator 1.7.2 on a MacBook Pro with OX 10.10.5 loaded. It seems to run fine for the most part, but I am trying to import some VPP codes for a couple paid apps without success. When I click on the number next to the app name, and click the Import Codes button, I can direct it to my spreadsheet and it will show a list of codes. When I press Done, then I get a dialog box with a progress bar, which tells me "Apple Configurator is importing. This may take a few minutes to complete." The next line says "Finished importing redemption codes for Book Creator for iPad" . Below that is a filled in progress bar and a cancel button. Despite the fact it's been there 30 plus minutes, nothing else has happened.

If I click the cancel button, nothing happens.

If I try to quit Configurator, the MBP just dings once but nothing happens.

If I force quit, the app I imported no longer shows and I have to start over.

Not sure what else to do! Please help.