Change End User property of Everyone Role folder permission

Hi,

We are using EP 7.3. I was supposed to change the permission of a folder where I had to add everyone role to it and check the the end user check box for the same. After adding the Everyone role, I saved before checking on the end user box. Now, the everyone role is disabled and I'm unable to edit it. I need to be able to modify the everyone role and check the end user check box. Please advise.

Thanks,

Ash