Magnolia 6.0 reached end of life on June 26, 2019. This branch is no longer supported, see End-of-life policy.
Version 6.0 of the UI project contains a "bridge" modus which lets backend users access the AdminCentral with the "old" look and feel as known from Magnolia 5.7.
To get to "bridge" modus, change the URL the following way:
Instead of <protocoll>//<host>/context/.magnolia/admincentral
use <protocoll>//<host>/context/.magnolia/admincentral-m5
The bridge mode doesn't look completely identical to the 5.7 version