Nevermind, I figured it out with Dell Chat Support. Draining the flea power (powering down the system and removing all power) allowed me to update the iDRACs successfully. Still doesn't explain the error messages, but it at least allowed me to proceed with getting my hosts registered with OpenManage Enterprise.
I am trying to discover three servers in our environment using OpenManage Enterprise, and it finds all but three servers. I get an Http 404 error, specifically "Unable to perform mandatory actions for DISCOVERY operation." and not much more information than that. I compared the three problematic iDRACs with other iDRACs that were successful, and the settings, firmware and BIOS level are all the same. Redfish is turned on with all three iDRACs as well. I tried an iDRAC reset both through the GUI and using racadm racreset, but this does not help. I need to be able to manage these three nodes, any help is appreciated. Thanks!   Michaal Rutledge
Unable to discover servers - Http 404 received