Drop & recreate the Unifiedpush database on mysql (to be sure the test is not invalidated by existing data) Restart jboss: the tables will be created and a fresh UPS will be ready Run the mock-data-loader and create 1 app with 100 variants and 100 tokens Access the admin ui. If the wizard windows appear, dismiss it. You will get the 400 error The mock data loader can be cloned from: github.com:aerogear/ups-mock-data-loader You can run the mock data loader with the following command line: ./mock-data-loader.sh -u admin -p yourpassword -a 1 -v 100 -t 100 In the event the error does not pop up (rare), create 100 app with 1 variant and 1 token and then create again an app with 100 variants and 100 tokens.