Can't drag png files into tiled "unrecognized file format"

I keep trying to import the LPC Base Asset tiles but i keep getting the same error please help

If you drag a file onto Tiled it will generally try to open it as a map or tileset file. It currently does not recognize image files. I agree it would be helpful to add this and to open the “New Tileset” dialog for this case.

Tiled does allow dragging image files into the Tilesets view, in which case the “New Tileset” dialog is opened with that image file selected.