yes, that was the resource I was looking for.
Thank you Enrico!

Hi Enrico,

yes that was the issue, I modified the host file and everything works. 
Thank you!

Yes I used a host name on the instance VM.
I use the IP adress whem I'm connecting to the instance from the browser my local machine.

Yes, both are on the same host with the prefix.
The service registry is fine, all services have the FQDN and the instance prefix.
Yes, all the productiond are running. 

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.