We recently upgraded our single ArcMC from version 188.8.131.526.0 to version 184.108.40.2069.1. After we upgraded, we tried to "Update Agent", locally, on this ArcMC...and also tried "Update Agent" on the Loggers (all running version 220.127.116.1191.0). We received the same error on both attempts: "Error while executing 'Agent Upgrade' on the node: (insert either ArcSight component name and type here) update installation script failed to run.Could not find the res file". We ended-up manually uninstalling the old ArcMC Agent, on the local ArcMC, and manually installing the new ArcMC Agent (version 18.104.22.1684.1). However, we still have the same errors/issues trying to perform "Update Agent" on our Loggers from ArcMC.