Plasma6: Dolphin forget sidebar-settings and PDF Icons in Dolphin not shown

[meven]

Same as

Dolphin loses all sidebars when minimising

Hello all, since Plasam6 (Update and new installations) dolphin loses all sidebars when minimising. Is this a feature? How can i fix this? Thanks a lot

@Raffinade

In the new version under plasma6 there is no such thing in settings.

You must be missing the package that provides pdf thumbnails.
Check you have installed:

kdegraphics-thumbnailers

Or you can try the solution:

No PDF Previews in Dolphin