Strange error

hey everybody! recently I tried to run the code from this video : https://www.youtube.com/watch?v=ecK9-L9LzxQ&t=29s . But I have the following error from the text file.
Can somebody please help me out?
message.txt (37.5 KB)

You should go to https://start.vaadin.com

And the adapt the example

Because the example is with an old Vaadin version

Thanks! Do you also know or have any links that might help me create a register/login page, because on the site given I can’t connect the components

You have to go to the settings page. There you can see security

It’s access control settings

and further? because all what it shows is :
help.JPG

Now you download it