Issue:

When trying to run “yum updates” or “yum install” the “system is not registered with an entitlement server” error message is given

This system is not registered with an entitlement server. You can use subscription-manager to register.

Cause:

This issue can be caused when the system has RHEL (RedHat) repositories installed (generally by mistake) or by old, bad, extra yum plugins.
 
 

Resolution:

To fix this issue follow the steps below:
 

1. In your preferred editor (vi, vim, nano, etc.) open the “subscription-manager.conf” file

sudo nano /etc/yum/pluginconf.d/subscription-manager.conf
 
 

2. Inside the “subscription-manager.conf” file change enabled to 0 and save the file

enabled=0
 
 

3. Lastly issue the “yum clean all” command

yum clean all
 
 

You should now be able to run “yum” properly with successful installations and updates.