Hi Rob,
This update just came out today so this is probably a bug. We should have a minor update to patch it pretty quickly.
I have verified this bug and created a ticket for you with our dev team. They will address it at their next availability, most likely tomorrow during business hours.
If you are able to roll back to the previous design manager plugin (1.x) it may work for you in the mean time until we squash this bug tomorrow.
Also, you can always access designs on the front end via the URL {yourwebsite}/designs/ as that gallery is run by the main plugin.
Thanks
– Sean