Problem with registering objects

Hi, I am new here. I´ve finally managed to instal everything and wanted to take first steps in ABAB dictionary. And here´s a problem. I had to ask for trial license in order to work as developer. But after 3 fields created in my table this message poped up: https://lh4.googleusercontent.com/-npEYNxGYG0s/UHFsHjkAE2I/AAAAAAAAAD4/uH27ai1Q7zk/s865/abap%2520problem.jpg

Can sb. help me out?

Thanks for any advice.

Lukas