After upgrading the Vertica from 11.1 to 12.0. I am not able to start the database until I accept the EULA through AdminTools. The same scenario is not happening while upgrading from 11.0 to 11.0.
It is a known issue. I am able to reproduce the issue locally. We have let engineering know about this new behaviour. If possible, please open a support case so that we can share more details.