I am trying to send something to the trash. I got this warning.
There is nothing in my trash. I emptied it a few days ago.
I'm not a desktop expert, mostly I use CLI, and I can be wrong here, but look like the Location of trash-bin is not correct, as it say is in "/" folder
I think it' should be in /home/<user>/Desktop.
Or may be, you are trying to use the root's trash-bin instead of your own user trash-bin ?
As side note, ms_meme, you can delete a file without moving it to trash-bin, by pressing SHIFT-KEY, right clicking on the file and choosing "delete",
in this latter case the deleted file can't be recovered.