You have found the article you are looking for in your favourite database, but when you want to consult it, you get the following page:
What happened and what can you do?
Do not try to login in via this page, go back.
Example: https://scifinder.cas.org instead of https://scifinder.cas.org.passerelle.univ-rennes1.fr/
The link resolver, designed to give access, has not recognised you as a member of the University of Rennes 1 community.
Correct the link, search again, and it should work! You can use the “Rennes 1 Authentication” button.
If you still have the same problem, delete your browser history.
If the problem continues, you can submit a ticket.