How to enable Admin Panel in TYPO3

In order to make sure that the admin panel is visible when you are in backend, make sure that the following criteria are met:

1. Make sure you are logged in to the BE of same domain.

In a multi-domain setup, if you are logged in www.domain-a.com, and you try to view www.domain-b, then don’t expect the preview / admin panel to work.
This simply does not work!

2. user and/or group setup:

admPanel=1
admPanel {
enable.edit = 1
enable.edit.hide=1
enable.preview = 1
enable.cache = 0
enable.info = 1
module.edit.forceDisplayFieldIcons = 1
module.edit.forceDisplayIcons = 1
module.edit.forceNoPopup = 0
hide = 0
}

3. root template setup:

config.admPanel=1