Apple Configurator 2 won't prepare
Solution 1:
I had a similar issue and here is what worked after so many attempts: - Use iTunes to Restored the ipad to the Factory setting - After restore, when it gets to the point where you are asked to set it up as a new iPad or restore from a backup, click CANCEL - Connect it to Apple Configurator again and prepare it.
Solution 2:
When I unlinked my account to the IPad and used the configurator it worked on its own as expected.