If you followed correctly the instructions to deploy the app on an external web server, that message is probably caused by typos.

Please check these calls on lsengine_config.js:
ls.connection.setLSHost(null);
ls.context.setDomain(null);

should look like these:
ls.connection.setLSHost("yourhost.yourdomain.com");
ls.context.setDomain("yourdomain.com");

where the "yourdomain.com" part must exactly match between calls.

Please do this check and then return back to us.
Hope that helps.

Mone.