I am using 10.11.4 OS X. I don’t know when exactly these are not working - files don't appear on desktop. Drag & Drop and popping up context menu with right click are not working on Desktop. - I’ve googled this problem and found no solution. Does anyone have any suggestions to fixing this?
Just in case it's your preferences that have got corrupted somehow, you could try the following two commands in the Terminal:
$ defaults write com.apple.finder CreateDesktop true $ killall Finder