This new error you're getting is the result of SIM losing the server to iLO association. So it doesn't know which iLO belongs to its server. Let's not worry about that too much right now. It will go away if we ever get this working.
The fact that you got this error though, and the fact that you get into the endless loop of PXE booting, makes me thing you didn't get the server properly deleted in SIM.
Shut down the managed node.
On the CMS, go to 'all systems', select that server, and select its iLO, and click 'delete' at the bottom of the screen.
Then, log into the CMS and cd to /opt/repository/boot/pxelinux.cfg
In there you will see files with names that look like MAC addresses. You need to delete any files that match any of the MAC addresses on your managed server.
Once those files are deleted, try PXE booting the managed node again and let me know what happens. It should NOT loop, but instead boot into the RAMdisk and discover itself in SIM.
Watch the rediscovery on the console of the managed node. If it works, you should see the system start to reboot after about 2 to 5 minutes. If it stack traces going into the ramdisk, then we need to look elsewhere.
