Instead of running amp_enable right away, you should first check to make sure the upgrade completed all the way. Check the upgrade log in /var/log/upgrade. If it shows that it quit out early, then you'll want to open a support case to get help in making sure the upgrade completes. A successful upgrade will typically have a graceful exit. Otherwise you may be working with only partially upgraded code. Often reasons for this are:
1) rpm update issue
2) out of disk space issue
3) exited the upgrade by accident before it could complete