cannot update change to index page

Hi cvera. It means that the files haven’t been given writeable permission. Suggestion: instead of editing your index file and entire site on the server, you may want to edit your pages locally and re-upload the files via FTP. If you still insist on editing inside the files page, set the permissions of the theme’s files to 666. You will find those files in wp-content/themes and then another subdirectory, which is dependent upon which theme you’re running. Hope this helps!