Yes, incognito has resolved the issue for everyone and it also seems like we sometimes get this error on other pages, so it may not be related in any way to this plugin.
I’m marking this as resolved for now. Now that I have made it through the wizard, I have not seen the issue again.
Just tried logging in using incognito mode in my browser and that worked…
Have a couple of other users running into this as well. Would still be good to get to the bottom of it.