Raars's Blog

System : VMWare client – Red Hat Enterprise Linux Client release 5.11 (Tikanga)

error message :
subscription-manager list
output – No installed products to list

Solution :

copied file Client-Workstation-x86_64-863725dc49ba-71.pem from /usr/share/rhsm/product/RHEL-5/ to /etc/pki/product

and it fixed an issue