Single Article Not Shown After Moving WordPress Site

If you move your WordPress site to a new file directory only (not moving hosting), you might be able to see your new web home page is OK, but all the single articles no more shown if you click article title from home page.

You will get NOT FOUND error message.

The one reason is very possible: You just need to change Permalinks in Admin panel, and click Save button. you will see all your articles work now.