Hi Marious,
I faced the same scenario during my platform upgrade. now my issue got resolved.
Can you check the upgrade is running on your platform server? Else try to upgrade the development environment version to recent stable version. Try to reset your password once and try again.. There may be sync issue.
Still you are facing the issue, feel free to reach OutSystems support team (support@outsystems.com) for better solution by raising Support ticket. Refer how to raise OutSystems support ticket if required.
Thanks, Aadhavan S