You are attempting to open up an existing case record within the Lightning Experience and encounter an error similar to the following: Unfortunately, there was a problem. Please try again. If the problem continues, get in touch with your administrator with the error ID shown here and any other related details. ui.services.connection.api.PartnerConnectionException: UNKNOWN_EXCEPTION: An unexpected error occurred. Please include this ErrorId if you contact support. ui.services.connection.api.PartnerConnectionException: UNKNOWN_EXCEPTION: An unexpected error occurred. Please include this ErrorId if you contact support.