Now everything is working fine. I asked my hosting company to set the AcceptPathInfo feature for me. I guess my hosting doesn't allow me to do that via .htaccess (don't know why) in Moodle root folder. So, if you still are in trouble, try to ask your hosting company (if you are not using your personal PC as a server).
Text editors
image uploading
This discussion has been locked so you can no longer reply to it.