This is usually caused by a misconfigured .htaccess file or outdated permalinks. To fix this, Connect with FTP and rename the .htaccess file to .htaccess.bak, then log into the wp-admin panel and from the left hand column select Settings>Permalinks. Take note of which radio button is selected, select any other, Click “Save Changes” to save the changes then change it back to what was set before and save again. This will create a new .htaccess file and should repair the links. If this doesn’t Check out Hard Coded Links and Search and Replace.
