When connecting to a 7.5 via ACC - Webadmin the certificate is shown but now connection will be established. If you then type the URL of the 7.5 in the addressbar of the just opened browser window (ex: https://192.168.0.1:4444) you will be connected to the backend without any authentification using the CM_admin account.
As of now we were not able to reproduce the behavior you encountered. When confronted with a certificate, the original POST request to the WebAdmin needs to be resend in order to perform an SSO login - either your browser offers this functionality and prompts you if you want to resend the data or you will need to invoke the SSO call within ACC again, after you have accepted the certificate in your browser.
