I am using Kdenlive video editor but all my .kdenlive files are shown in Pantheon files with a blank icon. Googling arround and messing with the hicolor icon theme I have some results only if I change the default icon set via ElementaryTweaks to any different then 'elementary'. If I do this no matter that a lot elementary os specific icons are missing, all .kdenlive and .kdenlivetitle files has the corresponding mime type icons. If I revert back to the "elementary" icon theme - again they became blank.. It works like this even if I add corresponding icons application-x-kdenlive.png/.svg into elementary icon theme folder also.
in order to rebuild icon/mime caches I use
sudo update-icon-caches /usr/share/icons/*
sudo update-desktop-database
sudo update-mime-database /usr/share/mime/
gtk-update-icon-cache
The mime format is ok, because if I drag a .kdenlive file on the plank, it uses the appropriate icon also, but in Pantheon files the icon remains blank(white rectangle) no matter what I try to do.
Any idea how can I fix this?