This authentication failure can occur when your operator is pointing at an invalid application or access group (or of course if you just aren't authenticating correctly! :) ). If you cannot access your environment we can reset it for you.

But your profile need to be linked to an account :(

"You are not linked to an account. To be linked, ask your company’s Support Contact Administrator to link you. You will then be able to create and update requests to download software licensed to your organization."

So for a simple citizen, this solution is not valid.

And MyTrial for Plateform is really restricted, and even with Community Edition I didn't find a way (yet ?) to add Customer Service on it.