In rhel 7 server I am trying to install packages with yum. After getting error that I need to register my rhel7 with `subscription-manager` I got this error:

command:

```
subscription-manager register

```

output:

```
'NoneType' object has no attribute '__getitem__'

```

after some checks I saw that I need to unregister (the register command dident work but still) and clean the data, but still same error. 

The user and password are correct in the red hat website