CBE Practice Plarform error

Hello

Every time I try to access the CBE platform, I get this error below.
Do you know what I need to modify in my settings to make it work? To mention I tried from two different laptops and got the same error, despite logging into myACCA.

HTTP Status 500 – Unable to do Single Sign On or Federation.
type Status report

message Unable to do Single Sign On or Federation.

description The server encountered an internal error that prevented it from fulfilling this request.

Apache Tomcat/7.0.81

Many thanks
Rita