If you press Del, Krusader will MOVE files into Trash, instead of deleting them permanently. Shift+Del does not work as well (just nothing happens) I believe it is a regression, because before upgrading KUbuntu to 17.04 beta old Krusader worked perfectly.
And if you try to delete everything in ~/.local/share/Trash/ manually, Krusader will tell you: Could not rename file /home/dimanne/.local/share/Trash/files.
Just set Settings->Configure Krusader->General: "Delete Mode" Everything resolved?
My apologies, I overlooked the option. Everything is fine now.