@manu56
Mystique theme (both the basic theme 2.5.7 available from WordPress.org or the more advanced Atom version 3.3.2 from the developers site) is not fully compatible with any version of WordPress since 3.6
The main problems are with some theme settings options. While there are work-arounds for these, they require some skill with CSS and WordPress functions, and/or manual file uploads by ftp in some cases.
There are also sometimes problems changing templates of published pages/posts
Unless you are comfortable with modifying the theme (using a child theme preferably) then I’d say stay away from Mystique. If you are willing to experiment then Mystique is still a great theme (one of my favourite themes and I still use it).
The developer seems to have abandoned development and support for this theme unfortunately so an update is unlikely. However, you’ll find many solutions to bugs have been published by users – Google the problem.
