As of Thursday, December 14, 2017, customers that have purchased Dynamics 365 for Finance and Operations, Enterprise edition on-premises will see the message “Unable to load environment" next to the on-premises environments listed in Lifecycle Services. This warning message is displayed for each environment, whether it has been deployed, in a Dynamics 365 on-premises project. This is strictly a user-interface issue and there is no impact to any deployed on-premises environment. You can continue to use the on-premises as usual. We will release a hotfix when the issue has been resolved.