Hi @denijane, thank's for your reply.
It's some days since I last logged in. I use my mail address and it works now. May be there was a delay between account creation and possibility to use Aria.
Thank's again for you help and enjoy Aria and Opera

I have installed Opera today - mainly to test the Aria AI feature.
Account created, confirmed, logged in.
Unfortunately Aria asks me to create an account...
and log in....
Any hint to resolve this issue is very much appreciated