Some times Dolphin forget the setting, that i want it to show the sidebar (F9), i dont know why but it is not all the time but sometimes.
Another problem is, that Dolphin not shown anymore preview of PDF-Files.
In the old Dolphin under plasma 5, under Setting - Preview there is a markable point for “PostScript-, PDF- and DVI-Files”. In the new version under plasma6 there is no such thing in settings.
I’ve done all the things above, but there is no solution. i reinstalled kdegraphics-thumbnailers but no help and i removed .cache and .share/mime but no luck.
The entry in preview in dolphin “PostScript, PDF and DVI files” isnt shown as the preview of pdf files.