Can't start the advanced training - error page after question about notification

When I try to start the advanced training I first get a question about “receiving notifications regarding upcoming trainings” but no matter what I answer the “Save changes” button leads me to a error page?

Hi, did you manage to save the changes and login or are you still encountering this issue?
If still happening, open a ticket here and add a print screen. thanks! Andra

Just tried it now again it works. Something must have been wrong with poll at the moment.

Thanks!