Hi Jeffrey, thank you for the reply.
Unfortunately, that doesn't seem to be the issue.
According to the documentation, I first install the demo UCR instance (with IHE) and then the CV instance. The SSO activation takes place right after the UCR installation, and I encounter the problem even before installing the CV instance. Once the SSO is enabled, I log out to check if it works, and I get the error I showed in the post.

I also tried to stop and start the accesd gateways on the UCR instance but doesn't solve the problem unfortunatly.