The file manager now does not allow me to copy or move files.
Sure it does, if you're talking about Thunar. (You are
talking about Thunar, aren't you?)
You can grab hold of a file's icon in the right-hand pane and drop it onto a folder to move it there, or use the context menu (right-click and select "Cut" or "Copy", etc.), or highlight a file icon and select "Cut" or "Copy" from the "Edit" menu.