Detail: (Truncated due to length) [MissingFeature] Database [WSS_Content] has reference(s) to a missing feature: Id = [fc5e2840-0b48-42eb-9ad7-076f5add58ad]. The feature with Id fc5e2840-0b48-42eb-9ad7-076f5add58ad is referenced in the database [WSS_Content], but is not installed on the current farm. The missing feature may cause upgrade to fail. Please install any solution which contains the feature and restart upgrade…

Detail:  Using highly-privileged accounts as application pool or as service identities poses a security risk to the farm, and could allow malicious code to execute.  Solution:  The farm account should be removed from the local Administrators group on all servers in the farm.