If you have a bunch of text from Microsoft Word that you want to Copy/Paste into your website, please note that Word has a nasty of habit of pasting invisible stuff that you don't need or want. It can mess up the editor quickly in the wrong circumstances.
Fortunately, there is a way to Paste that is very easy and simple. If you click on the Paste button dropdown in the toolbar (looks like a little clipboard, top row on the left), you'll see some "Paste from Word" options. Please use one of those options, or we even recommend to go farther and use the "Paste Plain Text" option and re-format your text after pasting. It'll eliminate confusion and headaches in the future.